MAY 


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o 
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02 


PRINCIPLES   AND   PRACTICE 


BUTTER-MAKING 


A.  TREATISE  ON  THE  CHEMICAL  AND  PHYSICAL  PROPERTIES 

OF  MILK   AND   ITS   COMPONENTS 

THE   HANDLING   OF  MILK   AND   CREAM,    AND   THE 
MANUFACTURE   OF  BUTTER  THEREFROM 


BY 


G.  L.  McKAY, 

Professor  of  Dairyino  in  the  Iowa  State  College,  Ames,  la. 


AND 


C.  LARSEN,  M.S.A. 


Professor  of  Dairy  Husbandry,  Ko.  Dak.  Slate  College,  Brookin-ji,  >'.  I), 
formerly  Associate  I'rojessur,  Iowa  State  College,  Ames,  la. 


SECOND  EDITION,  REVISED    AND   ENLARGED. 
FIRST    THOUSAND 


JOHN    WILEY    &    SONS 

LONDON:    CHAPMAN    &   HALL,    LIMITED 

1908. 


Copyright.  1906,  1908, 

BY 

G.  L.  McKAY  AND  C.  LABSEN 


Stye  &rtenttfit  f  «BH 
«Bb*rt  Brutnwonb  anh  ffiomiiang 


PREFACE  TO  SECOND   EDITION. 


THE  science  of  dairying  is  constantly  broadening.  The 
methods  and  art  of  manufacturing  the  best  quality  of  butter 
have  gradually  changed  in  conformity  to  the  scientific  princi- 
ples involved,  ard  no  manufacture  of  butter  should  now  be 
undertaken  until  a  careful  study  has  been  made  of  the  prin- 
ciples governing  the  best  methods  of  manufacture. 

The  authors  admit  that,  in  our  present  state  of  knowledge 
and  experimental  progress,  it  is  in  some  instances  difficult 
to  distinguish  well  established  facts  from  those  not  universally 
confirmed;  hence  it  has  been  the  object  of  the  writers  to  give 
only  information  supported  by  the  preponderance  of  experi- 
mental evidence. 

The  first  edition  of  this  book  has  been,  in  a  manner,  well 
received,  indicating  the  work  has  met  with  general  approval. 
The  second  edition  has  been  carefully  revised,  and  two  chapters, 
one  on  "Creamery  Refrigeration"  and  one  on  "Economic  Oper- 
ation of  Creameries"  have  been  added  to  meet  an  indicated 
demand,  and  the  authors  hope  that  this  will  justify  the  use  of 
the  book  in  our  dairy  schools,  and  also  as  a  general  reference 
book  for  those  engaged  in  dairy  pursuits. 

The  authors  believe  that  the  subject  of  dairying  should  no 
longer  be  treated  as  a  whole,  and  for  this  reason  such  subjects 
as  Testing  Milk  and  its  Products,  Dairy  Bacteriology,  Cheese- 
making,  and  Technology  of  Milk  and  its  Products,  have  not 
been  treated  comprehensively  in  this  work.  In  connection 
with  the  practical  phase  of  butter-making  the  writers  have 


iv  PREFACE. 

endeavored  to  give  such  scientific  information  related  to  it 
as  may  be  of  interest  and  value. 

The  scientific  knowledge  has  been  acquired  from  time  to 
time  through  work  done  by  various  investigators  at  the  different 
Experiment  Stations.  To  all  of  these  men  who  have  searched 
for  and  discovered  facts  bearing  upon  dairying  the  authors 
wish  to  express  their  thanks  and  acknowledgment. 

It  may  be  added  that  the  statistics  and  tables  given  in  this 
work  have  been  quoted  from  noted,  reliable  authorities,  as 
indicated. 

The  authors  are  also  indebted  to  the  following  parties  for 
the  use  of  electrotypes:  Mower-Harwood  Co.,  and  Cherry 
Bros.,  Cedar  Rapids,  la.;  Creamery  Package  Co.,  Waterloo 
Cream  Separator  Co.,  and  Iowa  Separator  Co.,  Waterloo,  la.; 
Vermont  Farm  Machine  Co.,  Bellows  Falls,  Vt. ;  Jensen  Mfg. 
Co.,  Topeka,  Kans.;  Ox  Fiber  Brush  Co.,  Davis  Cream  Sep- 
arator Co.,  Borden  &  Selleck  Co.,  and  De  Laval  Separator 
Co.,  Chicago,  111.;  Wagner  Glass  Works,  and  J.  H.  Monrad, 
New  York,  N.  Y.;  Burrell  &  Co.,  Little  Falls,  N.  Y.;  Empire 
Cream  Separator  Co.,  Bloomfield.  N.  J.;  Dairy  Queen  Mfg. 
Co.,  Flora,  Ind.;  Dairy  Record,  St.  Paul,  Minn.,  and  W.  D. 
Hoard,  Fort  Atkinson,  Wis. 

G.  L.  McKAY. 
C.  LARSEN. 


CONTENTS. 


CHAPTER  I. 

PAGE 

COMPOSITION  OF  MILK 1 

1.  Definition  of  Milk 1 

2.  Composition  of  Milk 2 

3.  Variation  of  Total  Solids 3 

4.  Water 4 

5.  Fat  in  Milk 5 

6.  Properties  of  Fat 7 

7.  Glycerides  of  Fat 8 

8.  Theories  in  Regard  to  Films  Enveloping  Fat -globules 9 

9.  Classes  of  Fats 10 

A.  Volatile 11 

B.  Non-volatile 12 

10.  Composition  of  Butter-fat 13 

11.  Casein 15 

12.  Albumen > 16 

13.  Sugar 16 

14.  Ash 18 

15.  Gases  or  Taints  of  Milk 18 

16    Coloring  Matter 20 

17.  Other  Constituents  of  Milk.  .                                                        ...  20 


CHAPTER  II. 

MILK  SECRETION 22 

1.  Mammary  Gland  as  a  Secretory  Organ 22 

2.  Internal  Structure  of  Cow's  Udder 22 

3.  Theories  of  Milk  Secretion 25 

4.  Conditions  Affecting  Secretion  of  Milk 28 

5.  External  Appearance  of  Udder 29 

6.  Milk-fever 30 

v 


vi  CONTENTS. 

CHAPTER  III. 

PAGE 

PROPERTIES  op  MILK 31 

1.  Color 31 

2.  Flavor 31 

3  Opacity  of  Milk 31 

-   4.  Chemical  Reaction  of  Milk 32 

5.  Specific  Gravity  of  Milk 32 

6.  Natural  Separation  of  Milk  and  Cream 35 

7.  Adhesion  of  Milk 37 

8.  Viscosity  of  Milk 37 

9.  Specific  Heat  of  Milk 38 

10.  Effect  of  High  Heat  on  Properties  of  Milk 38 

A.  Destroys  nearly  all  Germs 39 

B.  Diminishes  Viscosity  or  Body 39 

C.  Drives  off  Gases 40 

D.  Imparts  a  Cooked  Taste 40 

E.  Precipitates  Albuminoid  and  Ash  Contents 41 

F.  Destroys  Properties  of  Enzymes 41 

G    Divides  the  Fat-globules 42 

H.  Caramelizes  the  Sugar 42 

I.  General  Remarks 43 

CHAPTER  IV. 

FERMENTS  IN  MILK 44 

1.  Definition 44 

2.  Size  and  Shape  of  Bacteria 45 

3.  Favorable  Conditions  for  Bacterial  Grov/th 45 

A.  Food 45 

B.  Temperature 46 

C.  Moisture 47 

4.  Unfavorable  Conditions  for  Bacterial  Growth 48 

5.  Kind  of  Germ  Found  in  Milk 49 

6.  Number  of  Bacteria  in  Milk 51 

7.  Sources  of  Bacteria  in  Milk 52 

8.  Effect  of  Thunder-storms  on  Souring  Milk   53 

CHAPTER  V. 

ABNORMAL  MILK 54 

1.  Colostrum  Milk 54 

2.  Salty  Milk 55 

3.  Bloody  or  Red  Milk 56 

4  Blue  Milk. .  57 


CONTENTS.  vii 

PAGE 

5.  Yellow  Milk , 57 

6.  Ropy  Milk 58 

7.  Bitter  Milk 58 

8.  Milk  from  Cows  which  have  been  in  Milk  a  Long  Period 60 

9.  Milk  from  Spayed  Cows 61 

10.  Milk  from  Sick  Cows 62 

CHAPTER  VI. 

VARIATION  OF  FAT  IN  MILK 65 

1.  Individuality  of  Cows 65 

2.  Breed  of  Cows 67 

3.  Time  between  Milkings 68 

4.  Manner  of  Milking / 70 

5.  Milking-machines 7la 

6.  Fore  Milk  and  After  Milk 73 

7.  Age  of  Cow 74 

8.  Lactation  Period 74 

9.  Food  of  Cows 75 

10.  Environmental  Conditions. 76 

CHAPTER  VII. 

RECEIVING,  SAMPLING,  AND  GRADING  MILK  AND  CREAM 77 

1.  Receiving  and  Grading  of  Milk  and  Cream. 77 

A.  Detection  of  Abnormal  Milk  Through  the  Senses 79 

B.  Use  of  Acid  Tests 80 

C.  Use  of  Fermentation  Tests 81 

a.  Gerber  and  Wisconsin  Curd  Tests 81 

D.  Grading  Milk  by  Heating. 82 

E.  Use  of  Babcock  Test  and  Lactometer 84 

2.  Necessity  of  Good  Milk 89 

3.  Sampling  of  Milk 93 

4.  Sampling-tube 94 

5.  Sampling  Churned  Milk 96 

6.  Frozen  Milk •. 96 

7.  Sour  and  Coagulated  Milk 97 

8.  Apportioning  Skimmed  Milk 97 

CHAPTER  VIII. 

COMPOSITE  SAMPLES 99 

1.  Definition 99 

2.  When  to  Sample 99 


X  CONTENTS. 

PAGE 

^    .      e.    Proper  Utilization  of  Steam  Turned  into  the  Pas- 
teurizer   1 82 

C.  The  Cost  of  Pasteurization 183 

D.  Advancement  of  Pasteurization 183 

E.  Advantages  of  Pasteurization 184 

F.  Disadvantages  of  Pasteurization 186 

CHAPTER  XIV. 

CREAM-RIPENING 187 

1.  Definition 187 

2.  Objects  of  Cream-ripening 187 

A.  Production  of  Flavor  and  Aroma 187 

B.  Increases  the  Churnability  of  Cream 191 

C.  Increases  the  Keeping  Quality  of  Butter ^  192 

3.  Ripening  Temperature  of  Crtam 194 

4.  Amount  of  Starter  to  Add  to  Cream 196 

5.  Stirring  of  Cream  during  Ripening 197 

6.  Natural  Ripening 198 

7.  Artificial  Ripening 199 

8.  Ripening  Cream  when  Churning  i.s  Done  Every  Other  Day 201 

9.  Mixing  of  Cream : 202 

A.  Quality  of  Cream 203 

B.  Kind  of  Market 204 

C.  Amount  of  Cream 204 

D.  General  Creamery  Conditions 205 

10.  Examining  and  Testing  Cream  for  Acidity  during  Ripening.  .  .  .  205 

11.  Mann's  Test 206 

12.  Farrington's  Test 208 

13.  Amount  of  Acid  to  Develop 208 

14.  Changes  in  Cream 210 

A.  Physical 210 

B.  Biological 210 

C.  Chemical 211 

CHAPTER  XV. 

STARTERS 216 

1.  Definition 216 

2.  History 216 

3.  Classification  of  Starters 216 

4.  Preparation  of  Natural  Starters 217 

5.  Commercial  Starters  or  Pure  Cultures 217 

6.  Preparation  of  Commercial  Starters 218 

7.  Inoculation .  220 


CONTENTS.  Xl 

PAGE 

8.  Length  of  Time  a  Starter  Can  be  Carried 222 

9.  Poor  Starters 223 

10.  Under-ripening  and  Over-ripening  of  Starters 223 

11.  Amount  of  Starter  to  Use 224 

12.  Use  of  Starter-cans 225 

CHAPTER  XVI. 

CHURNING  AND  WASHING  BUTTER 226 

1.  Definition 226 

2.  Conditions  Affecting  the  Churnability  of  Cream 227 

A.  Temperature 227 

B.  Richness  of  Cream 231 

C.  Amount  of  Cream  in  Churn 233 

D.  Degree  of  Ripeness 234 

E.  Nature  of  Agitation 235 

F.  Size  of  Fat-globules 236 

3.  Straining  of  Cream 238 

4.  Color 238 

5.  When  to  Stop  the  Churning  Process 239 

6.  Churning  Mixed,  Sweet,  and  Sour  Cream 243 

7.  Difficult  Churning 243 

8.  Keeping  Churn  in  Sweet  Condition 245 

9.  Washing  of  Butter 247 

A.  Purpose  of  Washing 247 

B.  Temperature  of  Wash-water 247 

C.  Kind  of  Wash-water  to  Use 248 

10.  Methods  of  Purifying  Wash-water 250 

A.  Filtration 250 

a.  Continuous 253 

b.  Intermittent 254 

B.  Pasteurization 250 

11.  Advantages  of  Purification  of  Wash-water 255 

CHAPTER  XVII. 

SALTING  AND  WORKING  OF  BUTTER 256 

1.  Amount  of  Salt  to  Use  to  Produce  Proper  Flavor 256 

2.  Effects  of  Salt  upon  Keeping  Properties 258 

3.  Salt  Facilitates  the  Removal  of  Buttermilk 259 

4.  Salt  in  Relation  to  Water  in  Butter 259 

5.  Gritty  Butter 263 

6.  Mottled  Butter 263 

7.  Brine-salting 264 

8.  Objects  of  Working  Butter 266 


xii  CONTENTS 

CHAPTER  XVIII. 

PAGE 

PACKING  AND  MARKETING  BUTTER 269 

1     Kind  ot  Package  to  Use 2C9 

2.  Preparation  of  Tubs „ 271 

3    Packing  of  Butter 273 

4.  Packing  Butter  for  Exhibition  Purposes 275 

5.  Storing  Butter  in  Creameries 276 

6.  Cost  of  Producing  One  Pound  of  Butter 278 

CHAPTER  XIX. 

COMPOSITION  OF  BUTTER 281 

1.  Average  Composition 281 

2.  Effect  of  Composition  of  Butter  on  Quality 281 

A.  Curd  and  Sugar 282 

B.  Salt 282 

C.  Water 283 

D.  Fat 286 

CHAPTER  XX. 

JUDGING  AND  GRADING  BUTTER 287 

1.  Standard  for  Judging 287 

2.  Manner  of  Judging 290 

A.  Body 290 

B.  Flavor 290 

C.  Color 291 

D.  Salt 292 

E.  Style 292 

3.  Classification  of  Butter 292 

4.  Grades  of  Butter 293 

5.  Export  Butter 307 

CHAPTER  XXL 

COOLING  FACILITIES  FOR  CREAMERIES 309 

1.  Cooling  Systems 309 

2.  Natural    Ice-system 312 

A.  Kind   of  Ice-house 312 

B.  Size  and  Shape  of  Ice-house 31G 

C.  Filling  the  Ice-house 319 

D.  Source   of  Ice 321 

3.  Usage  of  Ice   in  Cooling  Cream 321 

A.  Directly. 

B.  Indirectly 


CONTENTS.  xiii 

4.  Mechanical  Refrigeration 323 

A.  Application  of,  in  Creameries 323 

B.  Chemicals  Used  for  Mechanical  Refrigeration 324 

C.  Principles  of  Producing  Cold  Artificially 324 

a.  Compression. 

b.  Condensation. 
C.   Expansion. 

D.  Transferring  the  Cold 326 

CHAPTER  XXII. 

ECONOMIC  OPERATION  OF  CREAMERY 329 

1.  Firing   the  Boiler 329 

2.  Burning  Wood  or  Coal 330 

3.  Daily  Weighing  of  Coal  Used 331 

4.  Cleaning  the  Boiler 332 

5.  Priming  of  Boilers 332 

6.  The  Injector 333 

7.  Oil-separators 333 

8.  Belts,  Pulley,  and  Speed  Calculation 334 

APPENDIX. 

I.  LEGAL  STANDARDS  FOR  MILK — DAIRY  LAWS 335 

II.  METRIC  SYSTEM  OF  WEIGHTS  AND  MEASURES  WITH  TABLES  FOR 
CONVERTING  THEM  INTO  CUSTOMARY  UNITED  STATES  EQUIV- 
ALENTS AND  THE  REVERSE  .  .  .  336 


BUTTER-MAKING. 


CHAPTER  I. 
COMPOSITION  OF  MILK. 

Definition. — Normal  milk  is  a  liquid  secreted  in  special 
glands  of  all  females  belonging  to  the  mammalian  group.  It 
is  composed  chiefly  of  water,  proteids,  fats,  sugar,  and  minerals. 
Coloring-matters  and  gases  and  some  organic  acids  are  found 
in  small  quantities. 

All  normal  milk  from  the  different  classes  of  animals,  such 
as  mare,  buffalo,  goat,  ewe,  ass,  and  cow,  has  a  general  resem- 
blance in  that  it  all  contains  water,  fat,  proteids,  sugar,  and 
ash.  But  milk  from  different  animals  varies  in  the  relative 
proportions  of  its  constituents.  The  chemical  and  physical 
properties  are  not  alike.  Human  milk,  when  treated  with 
half  its  volume  of  ammonium  hydrate  and  the  mixture  kept 
at  a  temperature  of  60°  centigrade  for  about  twenty  minutes, 
assumes  an  intense  red  color.  Cow's  milk  turns  faintly  yellow 
if  treated  in  the  same  way.  This  test  was  reported  by  Unikoff, 
of  St.  Petersburg,  at  the  meeting  of  the  Medical  Section,  Royal 
Academy  of  Medicine,  in  Ireland.  The  various  kinds  of  milk 
also  differ  from  each  other  in  their  behavior  towards  rennet. 
Richmond  has  divided  milk  into  two  classes:  Class  I  includes 
milk  from  the  ewe,  buffalo,  goat,  and  cow.  When  rennet  is 
added  to  the  milk  from  these  animals,  the  casein  coagulates  into 
a  firm  curd.  Class  II  includes  human  milk,  milk  of  the  ass, 
and  mare.  When  rennet  is  added  to  the  milk  of  these  animals, 
a  soft  curd  or  none  at  all  is  formed.  The  latter  class  seems 


BUTTER-MAKING. 


to  include  the  animals  without  horns,  while  the  first  includes 
those  with  horns. 

As  the  cow's  milk  is  used  chiefly  as  a  food,  it  has  been 
subjected  to  more  extended  and  more  careful  investigation 
than  the  milk  of  other  animals,  and,  as  a  consequence,  more 
definite  knowledge  has  been  obtained  concerning  its  com- 
position, properties,  and  uses.  The  succeeding  discussions 
have  reference  to  cow's  milk,  if  not  otherwise  stated. 

Composition  of  Milk. — It  is  impossible  to  get  accurate 
figures  on  the  composition  of  milk,  as  each  of  the  milk  con- 
stituents is  subject  to  fluctuation  from  various  conditions, 
such  as  individuality  of  cow,  breed,  season  of  the  year,  lacta- 
tion period,  milking,  and  environment. 

The  average  composition,  as  determined  by  200,000  analyses 
reported  by  Richmond  as  follows: 

Water 87.10 

Fat.. 3.90 

Milk-sugar 4. 75 

[  Casein 3 

{  Albumen 4 

Ash..  .75 


Proteids 


The  composition  of  various  kinds  of  milk  is  given  by  Konig 
as  follows : 


No.  of 
Analy- 
ses. 

Water. 

Fat. 

Casein 
and 
Albumen. 

Milk- 
sugar. 

Ash. 

Specific 
Gravity. 

Human       

107 

87.41 

3.78 

2.29 

6.21 

.31 

1    0270 

Mare    

50 

90.78 

1.21 

1.99 

5.67 

.35 

1  0347 

Buffalo     

8 

82.25 

7.51 

5.05 

4.44 

.75 

1  0350 

Ass  

7 

89.64 

1.64 

2.22 

5.99 

51 

1  0345 

Cow  

793 

87.17 

3.69 

3.55 

4.88 

.71 

1  0316 

Ewe     

32 

80.82 

6.86 

6.52 

4.91 

.89 

1  0341 

Goat  

38 

85.71 

4.78 

4.29 

4.46 

.76 

1.0328 

Sow  

8 

84.04 

4.55 

7.23 

3.23 

1.05 

1.038 

Bitch      

28 

75.44 

9.57 

11.17 

3.09 

73 

1  035 

Elephant  

3 

79  30 

9  10 

2.51 

8.59 

.50 

1.0313 

Hippopotamus   .  . 

1 

90  43 

4  51 

4.40 

.11 

Camel  

3 

86.57 

3.07 

4 

5.59 

.77 

1.042 

Llama  

3 

86.55 

3.15 

3.90 

5.60 

.80 

1.034 

COMPOSITION  OF  MILK. 

Variation  of  Total  Solids. — As  applied  to  milk,  "Total 
Solids/'  is  a  term  that  includes  fat,  casein,  albumen,  sugar, 
and  ash;  in  other  words,  all  the  milk  constituents  except  the 
water.  " Solids  Not  Fat"  is  a  term  often  used,  and  includes 
the  casein,  albumen,  sugar,  and  ash,  or  all  the  milk  constituents 
except  water  and  fat.  "  Serum  "  is  a  term  used  to  designate  all  the 
milk  constituents  except  the  fat.  The  fat  is  the  most  valuable 
constituent  of  the  total  solids.  The  variation  in  the  total 
solids  of  milk  during  the  summer  months  is  shown  in  the  table 
quoted  below  from  Dr.  Van  Slyke  of  Geneva,  New  York: 

m     ii.  Per  Cent          Per  Cent  of 

lonth-  of  Water.        Total  Solids. 

May 87.44  12. ,56 

June 87.31  12.69 

July 87.52  12.48 

August 87.37  12.63 

September 87  13 

October 86.55  13.45 

Dr.  Van  Slyke  also  studied  the  effect  of  the  lactation  period 
upon  the  total  solids  in  milk.  A  herd  of  fifty  cows,  calving 
in  different  months  of  the  year,  was  used  in  the  experiment. 
The  per  cent  of  total  solids  of  this  herd  seems  to  average  a 
little  high  all  through  the  ten  months.  The  total  solids  were 
found  to  be  14%  during  the  first  month,  decreasing  to  13.47% 
during  the  next  two  months,  then  gradually  increasing  with  the 
advance  of  the  lactation  period.  In  the  tenth  month  the  average 
total  solids  was  14.83%.  Pingree,  of  Pennsylvania,  reports 
having  found  normal  milk  from  a  cow,  which  contained  17.01% 
total  solids.  Sherman  *  reports  a  very  high  average  total  of 
the  milk  solids.  He  treated  the  milk  from  thirteen  cows, 
and  found  it  to  contain  on  an  average  18.03%  of  total  solids. 
Konig  reports  a  minimum  of  total  solids  of  9.31%,  a  maximum 
of  19.68%,  and  an  average  of  12.83%.  The  average  total 
solids  quoted  above  from  Richmond  is  12.90%,  which  agrees 
closely  with  Konig's  results. 

*  Journ.  Am.  Chem.  Soc. 


4  BUTTER-MAKING. 

The  difference  in  total  solids  of  milk  from  some  of  the 
leading  breeds  has  also  been  studied  by  Dr.  Van  Slyke,  and 
the  results  are  as  follows: 

TJ__-.,  Per  Cent         Per  Cent  of 

of  Water.        Total  Solids. 

Holstein 88.20  11.80 

Ayrshire.. 87.25  12.75 

Shorthorn 85 . 70  14 . 30 

Devon 85.50  14.50 

Guernsey 85.10  14.90 

Jersey 84.60  15.40 

The  maximum  and  minimum  amounts  of  total  solids  men- 
tioned above  are  abnormal  cases.  The  normal  variations  of 
the  solids  in  milk  are  within  comparatively  narrow  limits. 
For  this  reason  the  minimum  standard  for  total  milk  solids, 
in  states  where  dairy  laws  are  in  force,  is  fixed  by  law.  Usually 
12%  is  the  minimum. 

Water. — From  what  has  been  said  above  concerning  the 
total  milk  solids,  it  will  be  seen  that  water  constitutes  by  far 
the  largest  portion  of  milk.  It  is  quite  uniform,  and  in  milk 
from  a  mixed  herd  the  water  seldom  falls  below  86%  and 
seldom  exceeds  88%.  Variations  ranging  from  a  little  less 
than  80%  to  a  trifle  over  90%  are  on  record.  But  such  varia- 
tions must  be  looked  upon  as  occurring  in  only  a  very  few  special 
cases. 

It  has  often  been  asserted  that  cows  in  the  spring  of  the 
year,  when  they  are  pasturing  on  new  grass,  or  feeding  on  other 
succulent  foods,  yield  milk  which  contains  an  excess  of  water. 
Under  such  conditions  there  is  a  tendency  for  cows  to  pro- 
duce milk  with  a  water  content  a  trifle  higher,  as  has  already 
been  shown  by  the  figures  quoted  from  Dr  Van  Slyke.  As  a 
rule  this  is  much  overestimated.  It  is  even  a  common  occur- 
rence to  hear  creamery  operators  say  that  their  "soft"  or 
"slushy"  butter,  in  the  early  spring,  is  due  to  the  excess  of  the 
water  present  in  the  milk.  This  particular  phase  will  be  dis- 
cussed further  under  the  heading  of  "Fats  in  Milk." 

The  question  has  often  been  raised:   Is  the  water  in  milk 


COMPOSITION  OF  MILK.  5 

the  same,  or  any  more  valuable  than  water  obtained  from 
other  natural  sources?  The  water  in  milk,  so  far  as  known,  is 
transuded  from  the  blood-vessels  in  the  udder  into  the  milk 
glands.  It  is  so  perfectly  mixed  with  the  other  milk  con- 
stituents, and  holds  the  milk  solids  in  such  perfect  emulsion 
and  solution  that  it  would  seemingly  be  impossible  to  prepare 
milk  so  perfectly  by  artificial  means.  However,  a  substance 
is  prepared  by  Jacob  C.  Van  Marken,  Neuweid,  Germany, 
which,  when  added  to  water,  produces  a  substance  similar  in 
appearance  to  watered  skimmed  milk.  The  preparation  is 
named  "Kalberrahm  Vita."  The  first  name  literally  means 
calf-cream.  It  has  a  syrupy  consistency,  and  in  appearance 
resembles  light-brownish  molasses.  It  is  sold  in  tin  cans,  and 
recommended  highly  for  calf-feeding  when  mixed  with  skimmed 
milk.  When  mixed  with  water,  it  is  recommended  highly  for 
hog-feeding. 

Water  distilled  from  milk  has  the  same  appearance  as  ordi- 
nary distilled  water.  It  is  clear  and  colorless.  The  chemical 
reaction  when  phenolphthalein  is  used  as  an  indicator,  is  neutral, 
the  same  as  that  of  ordinary  distilled  water,  even  when  dis- 
tilled from  milk  in  which  acid  has  developed.  But  there  is 
a  considerable  difference  in  the  taste  and  smell.  This  indi- 
cates that  some  of  the  volatile  substances  are  distilled  over  with 
the  water.  The  probability  is  that  these  flavoring  substances 
are  so  closely  associated  with  water  in  milk  that  they  are  in- 
separable, and  that  the  only  place  where  this  water  can  be 
prepared  so  as  to  assume. these  qualities  is  in  the  cow's  udder. 
The  conclusion  would  then  be  that  the  water  in  normal  cow's 
milk  cannot  be  distilled  and  substituted  again  by  natural 
water  and  the  product  retain  its  normal  good  flavor. 

FAT  IN  MILK. 

This  is  by  far  the  most  important  constituent  of  milk, 
especially  to  creamery  operators.  It  exists  in  the  milk  in  sus- 
pension, in  the  form  of  globules  so  small  as  to  be  invisible 
to  the  naked  eye.  According  to  the  best  authorities,  fat- 


6 


BUTTER-MAKING. 


globules,  at  ordinary  living-room  temperature,  are  present  in 
milk  in  a  liquid  form.     Cooling  the  milk  to  a  very  low  tern- 


0   -  °      .      o      .  ^    o     o  •/    o         • .   <S 

o  'o  •      O  •     «v      •  • 

v-'.vv.!;-&*--. 

o  °      .^  .'      O 

0  o       .    «  oo  „      , 

•     o        .   •  o  -  eft       o    • 

••         o      *        O        «  .      "^     .  O 


•v  .•:.-.••  .\-  ;*"  -o 


»^s°0c^^*-^0^o^ 


FIG.  1. — Microscopical  appearance  of  different  kinds  of  milk.      Magnified 
300  times.     (U.  S.  Farmers'  Bui.  No.  42. ) 

perature  (about  50°  F.)  hardens  them.    When  the  globules  are 
caused  to  unite,  as  in  churning,  they  also  solidify. 

The  size  of  the  fat-globules  is  very  minute,  and  varies  con- 


COMPOSITION  OF  MILK.  7 

siderably,  according  to  breeds,  individual  cows,  and  the  stage 
in  the  lactation  period.  The  globules  in  the  milk  from  the  same 
cow  also  vary  a  great  deal.  Lloyd  found  that  fat-globules  in 
Jersey  milk  to  be  from  8  to  12  micro-millimeters  in  diameter. 
Very  few  ^were  less  than  4  micro-millimeters  (a  micro-milli- 
meter is  Tiroo-  millimeter,  or  ^ginnr  of  an  inch).  The  majority 
of  the  fat-globules  in  milk  from  Shorthorn  cows  measured  from 
6  to  8  micro-millimeters  in  diameter.  According  to  Fleisch- 
mann,  the  size  of  fat-globules  varies  between  1.6  micro-milli- 
meters and  10  micro-millimeters  in  diameter.  A  Danish  in- 
vestigator maintains  that  the  diameter  of  fat-globules  is 
between  .0063  and  .00014  millimeters,  and  that  1  cubic  centi- 
meter of  milk  contains  from  2.6  to  11.7  million  globules.  He 
also  asserts  that  a  reflection  of  the  light  renders  it  very  difficult 
to  get  the  proper  size  of  the  fat-globules,  as  the  light  tends  to 
make  the  globules  appear  larger  than  they  are  in  reality. 

It  has  been  maintained  by  some  that  the  larger  fat-globules 
contain  fats  which  are  different  from  those  contained  in  the 
smaller  globules.  But  this  is  by  some  investigators  considered 
to  be  a  matter  of  conjecture.  Most  authorities  now  believe 
that  there  is  no  difference  in  the  kinds  of  fat  of  the  different- 
sized  globules,  even  though  some  experiments  *  show  that  fat 
composed  of  larger  globules  has  a  finer  flavor,  and  a  little  more 
oily  appearance. 

From  what  has  been  said,  it  will  be  seen  that  the  minute- 
ness of  the  fat-globules  is  almost  inconceivable.  They  were 
first  discovered  in  1697  by  A.  von  Leeuwenhoek.  The  minute 
state  of  division,  or  the  form  of  emulsion  in  which  they  exist 
in  milk,  renders  it  easy  to  digest  when  consumed  as  a  food. 

Properties  of  Fat. — The  specific  gravity  of  pure  butter-fat 
at  15°  centigrade  is  .93002.  The  refractive  index  of  butter- 
fat  at  22°  centigrade  is  on  an  average  1.459.  The  melting- 
point  of  pure  butter-fat,  as  now  determined,  varies  between 
32°  and  37°  centigrade.  (90°  F.  and  99°  F.) 

*  Gembloux,  Belgium,  Creamer}-  Jo.,  London,  No.  8,  Vol.  I. 


8  BUTTER-MAKING 

When  pure  butter-fat  is  rapidly  cooled,  it  solidifies  into  one 
solid  mass;  but  if  allowed  to  cool  gradually,  part  of  it  solidifies, 
and  part  of  it  remains  a  liquid  longer  than  other  parts.  This 
seems  to  indicate  that  some  fats  with  a  high  melting-point 
separate  out  from  the  fats  with  a  low  melting-point.  This 
behavior  of  pure  butter-fat  is  not  well  understood,  as  it  con- 
tradicts the  now  accepted  theory  that  the  different  fats  are 
in  chemical  combination  with  each  other,  rather  than  a  me- 
chanical mixture  of  different  glycerides  of  fat. 

Glycerides  of  Fat. — By  this  term  we  understand  that  the 
fatty  acid  radicals  are  in  chemical  combination  with  the  glycerol 
(glycerine)  radical,  thus: 

Fatty  acid  radicals. 
Glycerol  radical,    f  C4H702       (Butyric) 

C3H5    j  C18H3302  (Oleic) 


The  chemical  formula  for  glycerine  is: 

Hydroxyl  groups. 
Glycerol  radical.    !  OH 

C3H5  j  OH 

I  OH 

Comparing  these  two  formulas,  their  difference  and  simi- 
larity are  easily  observed,  and  the  reason  why  the  term  "Gly- 
ceride  of  Fat "  has  been  applied  to  such  a  compound  is  evident. 

Condition  of  Fat. — Whether  the  fats  in  milk  exist  in  chem- 
ical combination,  or  whether  they  exist  as  glyceride  of  butyrin, 
stearin,  olein,  etc.,  in  the  form  of  a  mechanical  mixture,  is  a 
question  in  dispute.  If  they  exist  in  the  latter  form,  the  com- 
position of  the  different  fats  must  be  thus: 

Butyrin.  Olein.  Stearin. 

fPTTO  (  P     TT     r»  f  P     TT     /~\ 

I  ^4n7V-/2  |  v./i8n33l^2  f  ^18-n-35v-'2 

C3H5  j  C4H702        C3H5  j  Ci8H3302        C3H5  ]  Ci8H3502    etc., 
I  C4H702  |  Ci8H33O2  !  Ci8H3sO2 


COMPOSITION  OF  MILK.  9 

and  the  total  fat  made  up  of  a  mechanical  mixture  of  these 
and  the  remainder  of  the  fats  in  butter-fat. 

Richmond  and  other  authors  believe  that  fat  probably  exists 
in  milk  chemically,  as  first  mentioned  and  illustrated;  because, 
if  the  fat  were  a  mixture  of  glycerine  tributyrate  with  other 
glycerides  of  fat,  butyrin  or  glycerol  tributyrate  could  be 
dissolved  out  by  the  use  of  alcohol.  But  this  is  not  the  case. 
Moreover,  if  butyrin  existed  separately  in  milk,  it  would  be 
possible  to  distill  it  off  under  reduced  pressure.  This  cannot  be 
done. 

Theory  in  Regard  to  Films  Enveloping  Fat-globules. — The 
extreme  minuteness  of  the  fat-globules  in  milk  renders  it  almost 
impossible  to  determine  by  direct  microscopical  observation 
whether  there  is  a  membrane  around  each  globule  or  not. 
Fleischmann  and  Lloyd  assert  that,  so  far  as  they  were  able 
to  detect,  there  is  no  real  membrane  surrounding  each  globule. 

The  theory  generally  accepted  in  the  past  was  that  the 
only  film  surrounding  the  fat-globules  was  simply  due  to  sur- 
face tension,  or  to  the  fact  that  the  molecules  of  the  fat  have 
a  greater  attraction  for  themselves  than  they  have  for  the 
molecules  of  the  serum,  in  which  they  are  held  in  suspension. 
In  support  of  this  two  things  are  considered : 

(1)  The  natural  milk-fat  may  be  removed  from  milk  and 
artificial  fat  substituted  in  its  place.     The  resultant  milk  has 
characteristics   similar   to   milk   containing  normal   fat;     that 
is,  the  emulsion  which  milk  forms  with  the  artificial  fat  is  ap- 
parently like  that  formed  with  the  natural  fat. 

(2)  If  there  were  a  special  albuminous  membrane  around 
each  fat-globule,   cream  should   contain  a  higher  percentage 
of  albuminoids  than  milk.     This,  Richmond  maintains,  is  not  so. 

Dr.  Storch  concludes  from  extensive  researches  that  there 
is  a  gelatinous  membrane  enveloping  the  fat-globules.  His 
conclusions  are  based  mainly  upon  the  first  three  reasons 
given  below.  The  other  facts  mentioned  also  support  his 
conclusions : 

(1)  When  milk  has  been  stained  with  ammoniacal  picro- 


10  BUTTER-MAKING 

carmine,  and    the    cream  washed  with  water  until  it  is  free 
from  milk-sugar,  a  stained  layer  is  present  around  each  globule. 

(2)  He  has  succeeded  in  isolating  this  gelatinous  substance 
from  cream  and  butter.     Owing  to  its  existence  in  these  two 
substances,  he  assumes  that  it  is  also  present  in  milk. 

(3)  When  ether  is  added  to  milk,  the  fat  globules  dissolve 
with*  difficulty,  unless  some  alkali  is  added  to  the  milk  first. 

(4)  Bichamp  maintains  that  when  ether  is  added  to  milk 
the  fat-globules  are  enlarged  due  to  the  ether  passing  through 
the  supposed  membrane  by  the  process  of  osmosis.     He  con- 
siders this  fact  sufficient  to  prove  that  there  is  a  membrane 
encircling  each  globule. 

(5)  Butter  containing  85  to  86%  fat  is  asserted  by  Rich- 
mond to  have  the  same  consistency  as  cream  containing  about 
72%   fat  at  the  same  tefmperature.     The  solidity  of  butter 
is  due  to  the  close  proximity  of  the  fat-globules.     Now,   if 
cream  with  less  fat  has  the  same  consistency  as  butter,  the 
proximity  of  the  fat-globules  must  be    equal  to  that  of  the 
butter;    this  would  indicate  that  there  is  a  membrane  and 
that  this  membrane  increases  the  size  of  the  fat-globules. 

(6)  The  fact  that  cream  separated  by  centrifugal  force  is 
more  easily  churned  than  cream  of  same  richness  separated 
by  gravity  methods,  would  also  be  explained  if  the  fat  glob- 
ules in  milk  had  such  a  membrane  surrounding  them. 

This  membrane,  or  what  is  believed  to  be  a  membrane, 
Storch  has  isolated  and  analyzed.  He  finds  it  to  consist  of 
94%  of  water  and  6%  of  proteid. 

The  reasons  deduced  by  Storch  are  strong;  and  the  behavior 
of  cream  and  butter  renders  it  probable  that  there  is  such  a 
membrane  enveloping  each  globule  of  fat. 

CLASSES  OF  FATS. 

There  are  two  great  classes  or  groups  of  fats  present  in  the 
butter,  namely: 

(1)  Volatile  and  Soluble, 

(2)  Non-volatile  and  Insoluble. 


COMPOSITION  OF  MILK.  11 

It  was  previously  stated  that  little  is  known  concerning 
the  way  in  which  the  fatty  acids  are  combined  with  glycerine 
in  the  milk;  but,  for  the  sake  of  convenience,  the  fats  will  be 
referred  to  as  if  they  exist  as  separate  glycerides  of  fat. 

The  terms  "  Volatile  "  and  "  Non-volatile  "  are  applied 
to  the  glycerides  of  fat,  or  to  the  fats  as  they  exist  in  butter. 
Strictly  speaking,  this  is  not  proper,  as  they  do  not  assume 
the  volatile  characteristics  until  the  glycerine  separates  from 
the  fatty  acids;  it  is  only  then  that  the  latter  becomes  volatile. 

Volatile  Fats. — The  first  group,  or  the  volatile  fats,  include 
butyrin,  caproin,  caprylin,  caprin,  and  laurin.  Butyrin  is  the 
one  present  in  the  largest  proportion.  Laurin  and  caprin  are 
partially  non-volatile.  Butyrin  is  the  most  important  fat 
belonging  to  the  volatile  group.  It  is  the  most  important 
quantitatively,  and  also  qualitatively.  So  far  as  is  known, 
butyrin  is  the  least  stable  of  any  of  the  butter-fats.  Under 
normal  conditions,  so  long  as  the  fatty  acid  remains  in  com- 
bination with  the  glycerol,  it  is  not  volatile  nor  soluble  in 
water  but  as  soon  as  separation  takes  place,  due  to  the  action 
of  micro-organisms,  or  to  the  effect  of  light  and  air,  then  it 
becomes  volatile,  and  escapes  in  the  form  of  gas.  According 
to  the  mass  of  evidence,  these  factors  are  the  chief  causes  of 
rancidity  in  butter. 

It  is  also  claimed  that  these  volatile  fats  have  the  special 
properties  of  absorbing  odors  and  gases  to  a  greater  extent 
than  any  of  the  other  fats.  This  absorption  takes  place  when 
fat  comes  into  contact  with  the  undesirable  taints.  For  this 
reason  it  is  essential  that  milk,  cream,  or  butter  be  kept  away 
from  any  foreign  undesirable  odors.  These  undesirable  taints 
may  also  be  imparted  to  the  fat  before  the  milk  is  drawn. 
If  the  cow  is  fed  on  undesirable  food  such  as  turnips,  onions, 
garlic,  etc.,  the  milk  from  the  cow  assumes  undesirable  char- 
acteristic flavors,  which  can- easily  be  recognized  in  the  finished 
product.  On  the  other  hand,  such  foods  as  well-cured  sweet- 
clover  hay,  and  bran,  seem  to  impart  desirable  flavors  to 
milk  and  butter. 


12  BUTTER-MAKING. 

The  presence  of  these  volatile  fats  in  butter  is  quite  uniform, 
and  is  a  distinguishing  feature  of  pure  butter-fat.  The  detec- 
tion of  adulteration  of  butter  with  foreign  fats  is  based  chiefly 
upon  the  presence  of  these  volatile  fats.  The  characteristic 
desirable  flavor  of  butter  is  also  believed  to  be  due  to  the  pres- 
ence of  the  volatile  fats.  The  volatile  fats  vary  but  slightly 
during  the  different  seasons  of  the  year.  They  are  present 
in  the  greatest  proportion  during  the  spring  and  early  summer 
months,  when  cows  are  fed  on  grass,  and  also  during  the  early 
stage  of  the  period  of.  lactation.  They  decrease  gradually 
as  the  lactation  period  advances. 

About  8%  of  the  total  fats  in  milk  is  volatile  fats. 

Non-volatile  Fats. — This  group  constitutes  about  92%  of 
the  total  fats  in  butter.  Chemists  now  agree  that  palmitin, 
stearin,  olein,  and  myristin  are  the  most  important  ones  to 
be  considered,  as  will  be  seen  from  the  table  quoted  from  Rich- 
mond. 

These  non-volatile  fats  are  of  special  importance,  as  the 
relative  amount  of  each  of  these  fats  largely  causes  the  varia- 
tion in  the  hardness  and  softness  of  the  butter  and  butter-fat. 
The  melting-point  of  these  different  fats  varies  according  to 
the  different  investigators:  olein  is  a  liquid  at  ordinary  tem- 
perature and  melts  at  about  41°  F. ;  stearin,  on  the  other  hand, 
has  .a  melting-point  of  about  150°  F. ;  palmitin  also  has  a  high 
melting-point,  namely,  about  142°  F. ;  myristin  melts  at  about 
129°  F. 

Olein  has  been  found  to  be  present  in  the  greatest  pro- 
portion during  the  spring,  when  cows  are  fed  on  grass.  When 
cows  are  fed  on  normal  dry  food,  as  in  the  winter  time,  it  is 
present  in  a  much  less  degree.  This,  together  with  the  small 
increase  of  volatile  fats,  is  the  cause  of  the  softer  butter  so 
frequent  in  the  spring.  The  hardness  of  the  butter  in  the 
fall  or  winter  is  due  chiefly  to  the  presence  of  a  slightly  increased 
amount  of  the  fats,  with  a  high  melting-point,  as  mentioned 
above. 

From  what  has  been  said  above,  one  is  led  to  believe  that, 


COMPOSITION  OF  MILK. 


13 


by  melting  a  sample  of  butter  which  contains  these  different 
fats,  the  fats  with  a  low  melting-point  would  melt  first,  and 
leave  the  remainder  in  an  unmelted  condition.  Such  is  not 
the  case.  Butter-fat  in  this  respect  behaves  a  good  deal  like 
different  metals  with  different  fusing-points.  When  they  are 
melted  and  mixed  together,  cooled  and  then  renielted  again, 
they  assume  a  common  melting-point.  It  is  the  same  way 
with  butter-fat.  It  melts  at  a  temperature  of  91°  to 
96°  F. 

As  the  body  temperature  of  cows  (about  101°  F.)  is  above 
this  temperature,  the  fat  globules  are  present  in  the  milk  in 
liquid  form  when  milk  is  first  drawn.  A  peculiarity  about 
these  fat-globules  in  milk  is  that  the  milk  and  fat  may  be  cooled 
down  below  the  melting-point  of  the  fat  of  butter  without 
the  fat-globules  in  milk  being  solidified.  It  requires  a  tem- 
perature of  between  60°  and  78°  F.  before  the  fat-globules 
in  milk  begin  to  solidify.  When  these  small  fat-globules  are 
caused  to  unite,  as  during  the  churning  process,  they  solidify 
at  higher  temperature.  This  behavior  of  the  fat  in  milk  evi- 
dently must  be  due  to  a  relative'  change  in  the  position  of  the 
molecules  of  fat  during  the  process  of  cooling  and  warming. 
No  definite  explanations,  so  far  as  is  known,  have  been  given 
for  this  condition  of  the  fat. 

The  non-volatile  fats  found  in  butter-fat  are  practically 
the  same  as  those  found  in  other  animal  fats. 

Composition  of  Butter-fat. — In  his  "  Daipy  Chemistry," 
Richmond  gives  the  following  composition  of  butter-fat,  repre- 
senting the  mean  results  obtained  by  different  observers: 


Fat. 


8%  Volatile. 


92%  Non-volatile. . . 


(-Butyrin 3.85% 

j  Caproin 3 . 60% 

ICaprylin...... 55% 

Caprin 1.9% 

Laurin 7.  _ 

Myristin 20. 2%  H 

Palmitin 25.7% 

Stearin 1.8% 

I  Olein 35% 


BUTTER-MAKING. 


Richmond  also  gives  the  percentage  of  glycerine  and  fatty 
acids  in  each  of  the  different  fats,   as  follows: 

Butyrin.  .  .     3.85%  yielding  3.43%  fatty  acids  and  1.17%  glycerine 


Caproin.  . 

.     3.60 

3.25 

Caprylin.  . 

.55 

.51 

Caprin.  .  . 

1.9 

1.77 

Laurin.  .  . 

7.4 

6.94 

Myristin.  . 

.   20.2 

19.14 

Palmitin  . 

.   25.7 

24.48 

Stearin.  .  . 

.     1.8 

1.72 

Olein.  .  .  . 

35 

33.60 

.86 

.10 

.31 

1.07 

2.53 

2.91 

.19 

3.39 

100 


94.84 


12.53 


PROTEIDS  (ALBUMINOIDS). 

The  proteids  of  milk  are  present  partly  in  solution  and 
partly  in  suspension.  They  are  present  in  a  very  complex 
chemical  form.  Some  of  the  chemists  reckon  as  many  as 
eight  different  albuminoids  or  proteids  in  milk.  Duclaux 
claims  that  there  are  only  two  kinds  of  albuminoids,  the  coagu- 
Idble,  and  non-coagulable  casein.  He  has,  by  the  use  of  a  fine 
filter,  been  able  to  separate  the  fat  and  the  coagulable  from 
the  rest  of  the  serum.  The  amount  of  coagulable  casein  is 
claimed  to  vary  considerably,  and  seems  to  depend  upon  the 
amount  of  lime  phosphate  present.  The  filtrate  which  Duclaux 
obtained  from  filtering  the  milk  was  clear  and  colorless,  which 
proves  that  the  removal  of  the  casein  was  quite  complete. 
In  order  to  remove  casein  from  milk,  a  special  filter  (Chamber- 
land)  is  employed.  Owing  to  this  fact,  we  may  consider  the 
casein  to  be  present  in  suspension  or  semi-solution.  Noted 
chemists,  such  as  Babcock,  Van  Slyke,  Duclaux,  Storch,  Ham- 
marsten,  Ritthausen,  and  Richmond,  disagree  upon  the  num- 
ber of  albuminoid  substances  found  in  milk,  and  upon  the 
chemical  behavior  of  each. 

For  all  practical  purposes  it  is  safe  to  mention  two,  namely, 
(1)  casein,  and  (2)  albumen.  Those  two  substances,  as  all 
agree,  are  present  in  milk,  and  constitute  practically  all  the 


COMPOSITION  OF  MILK.  15 

albuminoids  in  milk.  But  after  these  two  have  been  separated 
from  milk  a  slight  precipitation  can  be  obtained  by  treating 
the  filtrate  with  alcohol.  This  has  been  called  albumose  and 
also  lactoglobulin.  From  this  resultant  filtrate  can  again 
be  separated  a  very  small  amount  of  material  containing 
nitrogen.  Dr.  Babcock  has  obtained  a  substance  from  milk 
called  fibrin.  These  latter  substances,  however,  are  present 
in  minute  portions,  and  are  believed  by  some  of  the  best  scien- 
tists to  be  the  same  as  the  albumen,  and  their  presence  in  the 
filtrate  is  due  to  incomplete  precipitation  of  the  alburnen  in 
the  first  place. 

Casein. — Casein  is  by  far  the  most  important  of  all  of  the 
albuminoids.  It  is  the  substance  which  forms  the  curd  in 
cheese-making.  In  fresh  milk,  as  is  now  understood,  it  is  in 
chemical  combination  with  lime  salts.  It  is  on  this  account 
that  fresh  milk  shows  the  amphoteric  reaction,  which  will  be 
explained  under  the  "  Properties  of  Milk."  The  coagulation 
of  casein  by  the  addition  of  rennet  or  dilute  acids  is  thought 
to  be  due  to  this  union  between  the  casein  and  lime.  Fleisch- 
mann  refers  to  this  as  the  "caseous  matter"  of  milk.  The 
viscosity  of  normal  milk  is  believed  to  be  due  in  a  large  meas- 
ure to  this  condition  of  casein  in  milk.  It  causes  the  casein 
to  be  present  in  a  colloidal  condition.  When  milk  coagu- 
lates by  natural  or  by  artificial  means,  the  union  between 
the  casein  and  lime  phosphate  is  largely  broken. 

Casein  and  albumen  differ  in  composition,  in  that  the  casein 
contains  phosphorus  and  less  sulphur  than  does  albumen. 
Fleischmann  maintains  that  a  substance  called  nuclein  is 
associated  with  casein,  and  is  not  found  in  albumen. 

Casein  is  precipitated  by  the  use  of  rennet  and  dilute  acids, 
and  coagulates  spontaneously,  due  to  the  acid  formed  in  the 
milk.  The  precipitates  formed  by  the  use  of  different  pre- 
cipitating agents  are  not  alike.  The  curd  coagulated  by  ren- 
net contains  more  fat  and  calcium  phosphate  than  the  curd 
does  which  is  precipitated  by  dilute  acid  or  soured  sponta- 
neously. If  milk  stands  at  air  temperature  for  any  length 


16  BUTTER-MAKING. 

of  time  after  milking,  the  caseous  matter  (or  the  nitrogenous 
matter  combined  with  lime)  tends  to  separate.  The  caseous 
matter  of  milk  is  not  completely  precipitated  by  heat,  although 
heat  partially  destroys  the  union  between  the  casein  and  lime. 
This  destroys  the  action  of  rennet.  Instead  of  getting  a  smooth 
solid  coagulum,  a  more  flaky  precipitate  is  obtained.  For  this 
reason  milk  for  cheese-making  should  not  be  heated  to  a  high 
temperature.  By  heating  milk  in  a  glass  flask  to  a  high  tem- 
perature, and  letting  it  stand  for  a  time,  it  will  be  found  that 
a  mineral  precipitate  has  settled  to  the  bottom.  This  pre- 
cipitate is  believed  to  be  a  lime  phosphate,  which,  previous 
to  heating,  was  combined  with  the  casein  of  the  milk.  By 
adding  calcium  chloride  (CkCl2)  to  milk  which  has  been  heated, 
its  normal  condition  towards  the  action  of  rennet  is  again 
restored. 

Albumen. — If  the  casein  is  removed  from  the  milk  by 
precipitation,  and  then  filtered  off,  the  filtrate  will  contain  a 
•  substance  which  will  precipitate  when  boiled.  This  is  albumen, 
and  is  similar  in  character  to  albumen  from  the  white  of  an 
egg.  It  differs  from  casein  in  that  it  is  not  precipitated  by 
rennet  or  acids,  but  precipitates  on  heating.  It  does  not 
contain  any  phosphates,  but  contains  a  comparatively  large 
amount  of  sulphur. 

As  the  albumen  is  soluble  in  rennet  and  dilute  acids,  it 
can  readily  be  seen  that  it  is  retained  in  the  whey  obtained  in 
cheese-making.  When  albumen  is  present  in  small  quanti- 
ties, as  it  is  in  normal  milk,  heating  does  not  completely  pre- 
cipitate it,  unless  the  casein  or  curd  is  first  removed.  If,  on 
the  other  hand,  albumen  is  present  in  excess,  as  is  the  case 
in  colostrum,  the  major  portion  of  the  albumen  is  precipitated 
when  heat  is  applied,  without  first  removing  the  casein. 

Sugar.—  Milk-sugar  occurs  in  milk  to  the  extent  of  about 
5%.  It  varies  very  little  in  quantity,  seldom  falling  below 
3£%  and  seldom  rising  above  5£%.  It  occurs  in  solution, 
and  is  found  in  no  other  place  in  nature. 

Milk-sugar  is  the  most  unstable  component  of  milk.     It 


COMPOSITION  OF  MILK.  17 

quickly  and  easily  decomposes.  This  decomposition  is  caused 
by  micro-organisms.  If  these  could  be  entirely  excluded 
from  the  milk,  it  would  keep  for  an  almost  indefinite  length 
of  time.  As  it  is  impossible  under  practicable  conditions  to 
entirely  exclude  organisms  from  the  milk,  the  only  way  in 
which  the  growth  of  germs  can  be  retarded  and  prevented, 
and  thereby  prevent  the  changing  of  the  sugar  into  other 
products,  is  to  cool  the  milk  to  a  low  temperature  (50°  F.), 
or  to  heat  the  milk  to  a  sufficiently  high  temperature  (180°  F.) 
to  destroy  most  of  the  germs.  According  to  Van  Slyke  and 
Hart,  the  decomposition  of  the  caseous  matter  produces  free 
casein.  When  about  .5%  acid  has  developed  in  the  milk, 
the  free  casein  combines  with  the  acid  and  forms  casein 
lactate. 

The  chemical  composition  of  milk-sugar  is  C^H^On  +H2O. 
When  a  perfect  decomposition  of  milk-sugar  into  lactic  acid 
takes  place,  the  following  equation  would  represent  the 
change  : 

(Milk-sugar)     (Lactic  acid) 


Such  an  ideal  change,  however,  never  takes  place.  In 
such  a  case,  one  gram  of  milk-sugar  should  produce  one 
gram  of  lactic  acid.  In  a  number  of  experiments  carried 
on  by  one  of  the  authors  of  "  The  Analysis  of  Cream  During 
Different  Ripening  Stages,"  *  the  highest  amount  of  acid 
produced  from  one  gram  of  milk-sugar  was  .8  of  a  gram. 
This  indicates  that  there  are  always  accompanying  by-products 
produced,  besides  lactic  acid,  when  milk-sugar  is  being  decom- 
posed in  cream  or  milk.  The  sourness  of  milk  is  due  to  this 
change.  The  by-products  which  accompany  the  production 
of  lactic  acid  are  many  and  various.  The  most  important 
ones  are  gases  of  different  kinds,  such  as  carbonic  acid  gas 
(C02);  marsh  gas  (CH4);  hydrogen  (H);  and  nitrogen  (N).  A 

*  Thesis  I.  S.  C.,  Ames,  la. 


18  BUTTER-MAKING. 

small  amount  of  alcohol,  formic,  acetic,  and  succinic  acids  are 
said  to  be  normal  accompanying  by-products  also.  These 
by-products  may  also  partially  result  from  the  breaking  down 
of  some  of  the  other  milk  components. 

As  milk-sugar  is  in  perfect  solution,  it  follows  the  water 
of  milk,  and  in  cheese-making  nearly  all  of  it  passes  into  the 
whey.  Commercially  and  chemically  it  is  prepared  from 
whey.  It  is  a  white,  not  very  sweet  powder,  and  is  used  for 
medicinal  purposes  to  dilute  pure,  powerful  drugs.  It  is  also 
used  extensively  in  the  preparation  of  modified  milk. 

Ash. — The  ash  of  milk  is  present  in  very  small  quantities, 
and  when  viewed  from  such  a  standpoint  it  may  first  seem 
to  be  of  small  importance.  On  account  of  the  effect  of  the 
mineral  constituents  upon  the  properties  of  milk,  it  is  one 
of  the  most  important  components  of  the  milk.  It  consists 
partly  in  solution,  and  partly  in  suspension.  Babcock  main- 
tains that  about  one-third  of  the  tisual  ash  constituents  is  in 
suspension,  and  that  they  consist  chiefly  of  lime  phosphate. 

All  of  the  minerals  in  milk  consist  chiefly  of  potash,  lime, 
soda,  magnesia,  and  iron,  combined  with  phosphoric,  hydro- 
chloric, sulphuric,  and  carbonic  acid.  Calcium  phosphate 
constitutes  about  one-half  of  all  the  ash  constituents.  They 
are  named  above,  in  order,  according  to  the  extent  in  which 
they  occur  in  milk. 

Gases  of  Milk. — These  do  not  normally  exist  in  milk  to 
such  an  extent  as  to  enable  chemists  to  determine  them  quan- 
titatively, but  they  are  of  great  importance,  owing  to  the 
effect  they  have  upon  the  quality  of  the  milk,  viewing  it  in 
the  commercial  sense. 

Gases  in  milk  may  be  divided  into  two  classes  according  to 
their  origin;  namely,  (1)  those  imparted  to  milk  before  milk- 
ing and  (2)  those  which  are  formed  and  absorbed  in  milk 
later. 

(1)  When  freshly  drawn  milk  has  a  characteristic  cowy 
smell,  which  seems  to  be  normal  to  all  fresh  milk.  These 
gases  are  very  volatile,  and  by  cooling  and  aerating  milk  (differ- 


COMPOSITION  OF  MILK.  19 

ent  processes  of  which  are  now  in  use  in  this  country)  these 
gases  can,  to  a  large  extent,  be  eliminated.  The  amount  and 
kind  of  taints  existing  in  milk,  immediately  after  it  has  been 
drawn,  largely  depend  upon  the  food  which  the  cow  has  been 
fed.  Turnips,  onions,  and  garlic,  when  fed  to  cows  a  short 
time  before  milking,  cause  undesirable  gases  or  taints  to  exist 
in  the  milk.  Good  sweet  hay,  bran,  and  good  grass  are  said 
to  produce  milk  of  superior  quality,  and  containing  no  bad 
taints,  except  the  cowy  or  animal  taste,  which  is  natural  to 
all  milk  when  first  drawn. 

The  milk  yielded  by  cows  pasturing  in  the  Alps  of  Switzer- 
land is  said  by  tourists  to  possess  a  peculiar,  not  undesirable, 
spicy  odor  and  flavor.  It  is  maintained  by  the  native  people 
in  Switzerland  that  the  peculiar  flavor  of  tbe  Emmanthaler 
cheese  cannot  be  developed  anywhere  else  in  the  world.  This 
flavor  they  believe  to  be  due  to  the  kind  of  vegetation  the 
cows  feed  upon  in  the  Alpine  pastures.  In  Denmark,  the 
poor  people  who  do  not  own  much  land,  graze  their  cows  along 
the  roads  where  weeds  of  different  kinds  grow.  Milk  from 
such  cows  has  a  peculiar  characteristic  odor  or  taint.  In  this 
country  it  is  a  common  occurrence  to  find  that  milk  delivered 
by  patrons  who  keep  their  cows  on  timber-land  pastures  has 
a  peculiar  weedy  odor.  Especially  is  this  true  in  the  fall  or 
late  summer.  These  flavors  are  somewhat  difficult  to  remove 
by  the  ordinary  process  of  aeration.  By  heating  such  milk 
to  160°  or  180°  F.,  and  stirring  occasionally,  most  of  these 
taints  pass  off.  An  addition  of  a  small  amount  of  saltpeter 
also  improves  it. 

Too  much  emphasis  cannot  be  placed  upon  the  food  that 
the  cows  receive.  While  it  is  true  that  much  of  the  desirable 
aroma  and  flavor  in  butter  are  due  to  bacterial  growth,  the 
kind  of  food  fed  to  cows  is  not  without  significance.  It  is 
a  well  known  fact  that  districts  such  as  Normandy  and 
Denmark,  which  have  become  famous  for  their  high  quality 
of  dairy  products,  have  the  best  of  pasture  and  winter 
feeds. 


20  BUTTER-MAKING. 

Besides  the  kind  of  food,  some  physiological  disturbances 
of  the  cow  may  cause  abnormal  taints  in  milk. 

(2)  Gases  or  taints  which  are  formed  in  the  milk  or  absorbed 
by  the  milk  are  due  to  fermentation  and  absorption  respectively. 
The  fermentation  cause  will  be  considered  in  a  separate  chapter, 
and  the  latter  cause  needs  little  explanation.  It  is  a  well  known 
fact  that  milk,  or  any  of  its  products,  has  the  special  property 
of  absorbing  odors  which  may  be  present  in  the  surroundings 
of  milk.  For  this  reason,  milk,  as  well  as  other  dairy  products, 
should  at  all  times  be  kept  in  clean  utensils  and  pure  surround- 
ings. 

Abnormal  taints  appearing  in  milk  immediately  after 
milking  are  due  to  absorption  within  the  cow.  Taints  that 
develop  on  standing  are  due  to  bacterial  growth  in  the  milk, 
or  to  absorption  from  impure  surroundings.  In  removing 
undesirable  taints  from  milk  the  first  step  is  to  remove  the 
inciting  cause,  and  the  second  to  cause  as  many  of  these  taints 
as  possible  to  escape  by  a  process  of  aeration  or  pasteurization. 

Coloring-matter. — It  is  ^iot  known  of  what  the  coloring- 
matter  in  milk  consists.  A  substance  named  lactochrome 
has  been  found  in  milk.  So  far  as  known,  this  coloring-sub- 
stance is  closely  associated  with  the  fat  called  palmitin.  The 
amount  of  coloring-matter  varies  during  the  different  seasons 
of  the  year.  It  also  varies  according  to  the  different  breeds. 
During  the  spring  of  the  year,  when  cows  are  first  put  on  grass, 
the  color  of  the  butter-fat  is  always  higher  than  it  is  during 
the  latter  portion  of  the  summer.  During  the  winter,  the 
fat  in  milk  is  quite  pale.  By  feeding  the  cows  some  succulent 
feed  in  the  winter,  such  as  silage,  carrots,  and  beets,  the  color 
of  the  butter-fat  becomes  much  higher. 

From  this  it  would  seem  that  the  change  in  the  color  of 
the  fat  with  the  different  seasons,  and  the  food  fed,  is  closely 
associated  with  chlorophyl,  the  coloring-matter  of  grass. 

Other  Constituents  of  Milk. — It  is  said  that  constituents 
such  as  citric  acid,  urea,  nuclein,  lecithin,  and  galactase  are 
present.  Babcock  maintains  that  he  has  discovered  a  sub- 


COMPOSITION  OF  MILK.  21 

stance  named  fibrin.  This  seems  to  be  similar  to  the  nuclein 
mentioned  by  Fleischmann,  if  not  the  same.  But  as  these 
substances  are  present  to  a  very  small  extent,  citric  acid,  urea, 
and  fibrin  being  present  to  the  extent  of  .12,  .007,  and  .0002% 
respectively  (Fleischmann  and  Babcock),  they  are  of  little 
importance. 


CHAPTER  II. 

MILK  SECRETION. 

The  Mammary  Gland  as  a  Secretory  Organ.  —  The  mam- 
mary gland  of  females  belonging  to  the  order  of  mammalia, 
secretes  a  fluid  known  as  milk.  This  substance  is  strictly  a 
secretory  product.  There  are  two  kinds  of  glands  present 
in  the  animal  body;  viz.,  the  excretory  and  the  secretory.  Gen- 
erally speaking,  an  excretory  gland  is  one  which  receives  or 
absorbs  the  waste  matter  of  the  body,  and  causes  it  to  be 
carried  off  without  causing  any  marked  change  to  take  place 
in  the  substance  excreted.  A  secretory  gland  is  one  in  which 
the  raw  material  is  obtained  from  the  blood  and  then  manu- 
factured into  a  special  different  product  within  the  gland 
itself.  As  an  example  of  a  secretory  gland,  the  milk-gland 
of  the  cow's  udder  is  an  apt  illustration.  The  glands  in  the 
mouth  secreting  saliva,  and  those  in  the  walls  of  the  stomach 
secreting  the  digestive  fluids,  are  also  secretory  glands. 

Internal  Structure  of  Cow's  Udder.  —  The  cow's  udder  is 
composed  of  two  separate  glands,  the  right  and  left  halves. 
These  two  glands  are  distinctly  separated  from  each  other 
by  a  fibrous  tissue  running  longitudinally.  This  fibrous  par- 
tition extends  along  the  abdomen  in  front,  and  back  to  a  point 
between  the  thighs  of  the  cow.  It  also  serves  to  hold  the 
cow's  udder  in  place.  There  is  no  connection  at  all  between 
the  right  and  left  gland,  and  consequently  milk  cannot  be 
drawn  from  the  left  side  over  to  the  right,  and  vice  versa. 

Each  of  these  right  and  left  halves  is  again  divided  into 
two  parts,  thus  making  the  cow's  udder  appear  in  quarters. 
The  cow's  udder  may  then  be  said  to  consist  of  two  glands 

22 


MILK  SECRETION.  23 

on  the  right  side,  and  two  on  the  left  side.  The  divisions 
between  the  two  glands  on  the  side  are  not  entirely  complete. 
That  is,  there  is  enough  connection  between  the  two  glands 
on  the  same  side  to  allow  a  portion  of  the  milk  to  be  drawn 
from  the  rear  teat  to  the  front  teat  on  the  same  side,  and  from 


GLAND-LOBULE 
ALVEOLI 


FIG.  2. — Schematic  figure  showing  cross-section  of  cow's  udder;  and  also 
enlargement  of  epithelial  cells  in  alveoli  when  cow  is  giving  milk  (1).  Each 
alveolus  is  surrounded  with  a  membrane  called  tunica  propria.  Cell 
nuclei  not  shown.  When  cow  is  in  milk  they  are  also  enlarged.  When 
not  the  epitheliarcells  are  flat  and  the  nuclei  small  and  spindle  shaped  (2). 

the  front  teat  to  the  rear  teat.  The  milk-glands  proper  are 
located  near  the  abdomen  and  extend  downwards  into  the 
udder  a  trifle.  The  remainder  of  the  udder  is  filled  with  ducts, 
fibrous  and  connective  tissue,  muscle,  nerves,  and  blood-vessels, 
the  whole  udder  assuming  a  sort  of  spongy  and  open  condition. 


24  BUTTER-MAKING. 

The  teat  is  simply  a  cylindrical-shaped  body,  with  a  hollow 
tube  extending  down  through  the  center  of  it.  At  the  bot- 
tom of  this  opening,  or  at  the  end  of  the  teat,  there  is  a  sphincter 
muscle.  This  muscle  in  some  circumstances  is  drawn  up  very 
tight,  while  in  other  instances  it  is  so  loose  that  it  will  not  guard 
the  milk  from  escaping.  In  case  the  muscle  is  so  tight  that 
the  milk  can  be  drawn  only  with  difficulty,  it  may  be  relaxed 
a  trifle  by  entering  a  small,  smooth  wooden  plug.  This  will 
usually  dilate  the  opening  sufficiently,  so  that  the  milk  may 
be  drawn  with  comparative  ease.  In  some  instances  this 
muscle  is  so  tight  that  it  is  necessary  to  relax  it  by  the  use 
of  a  sharp  knife.  This,  however,  should  be  done  with  sur- 
gical skill;  otherwise  the  whole  muscle  is  likely  to  be  so  injured 
as  to  cause  the  milk  to  leak  away  at  all  times. 

The  upper  part  of  this  canal  in  the  teat  connects  with 
what  is  called  the  milk-reservoir.  The  size  of  this  reservoir 
varies  in  different  cows.  The  average  capacity  of  this  milk- 
cistern  is  about  one  pint.  The  opening  from  this  reservoir 
into  the  teat  is  also  guarded  with  a  muscle.  Over  this  muscle 
the  cow  has  little  control.  Over  the  muscle  at  the  lower  end 
of  the  teat  the  cow  has  no  control  whatever. 

Opening  into  the  sides  and  top  of  this  reservoir  is  a  large 
number  of  tubes,  which  are  called  milk-ducts.  These  milk- 
ducts  extend  from  the  reservoir  up  into  the  milk-gland.  They 
radiate  in  all  directions,  divide  and  subdivide,  so  as  to  form 
a  very  large  number  of  small  tubes.  These  milk-ducts  are 
surrounded  with  fibrous  muscular  tissue,  nerves,  and  blood- 
vessels. They  are  all  guarded  by  a  special  muscle  at  the 
junction  to  the  main  milk-ducts,  from  which  they  radiate. 
These  muscles  are  so  intimately  connected  with  the  nerves 
and  muscular  system  of  the  cow  that  she  is  able  to  open  and 
close  them  at  will.  There  are  very  few  cows  that  are  not 
able  to  hold  up  their  milk  during  nervous  and  exciting  periods. 
It  is  a  common  occurrence  for  a  milker  to  get  only  a  small 
part  of  the  milk  from  a  cow.  This  small  amount  is  the  portion 
which  is  present  in  the  teat  and  milk -reservoir.  Some  cows 


MILK  SECRETION.  25 

are  able  to  hold  up  this  mi]k  also,  but  the  majority  of  cows 
cannot  perfectly  control  the  muscle  which  guards  the  en- 
trance to  the  teat.  The  milk  which  is  present  in  the  milk- 
ducts  and  which  has  to  pass  through  these  junctions  referred 
to  above,  can  be  held  up  by  most  cows  at  will. 

All  of  these  small  milk-ducts  end  in  small  sack-like  bodies. 
Each  of  these  dilated  portions  is  called  the  gland-lobule 
or  ultimate  follicle.  These  gland-lobules  enclose  numerous 
individual  microscopical  bodies  called  alveoli  or  acini.  These 
alveoli  constitute  the  organs  which  possess  the  proper  secre- 
tory functions.  These  alveoli  are  lined  on  the  outside  with  a 
membrane  called  the  tunica  propria.  Next  to  this  membrane 
is  a  layer  of  cell-tissue.  The  inside  layer  is  composed  of  cells, 
which  are  named  the  epithelial  cells.  These  epithelial  cells 
within  the  alveoli  are  supplied  with  blood  from  the  cow's 
system.  During  lactation  they  assume  a  different  form. 
When  the  cow  is  yielding  milk  abundantly,  these  cells  swell 
and  extend  into  the  cavity  of  the  alveoli.  When  the  cow  is 
not  in  milk  these  alveolian  cells  become  flat.  A  certain  number 
of  alveoli  is  tributary  to  one  particular  duct  leading  from  the 
gland-lobule  into  still  larger  milk-ducts. 

Each  aggregation  of  gland-lobules,  tributary  to  one  milk- 
cistern,  constitutes  a  lobe,  and  may  be  likened  to  a  side  branch 
of  a  bunch  of  grapes.  Each  separate  grape  may  represent 
a  gland-lobule.  The  seeds  within  the  grape,  if  we  imagine  each 
seed  to  be  hollowed  out  and  lined  with  small  column-like 
bodies,  may  be  likened  to  the  alveoli.  These  column-like 
bodies  would  then  represent  the  epithelial  cells.  The  stem 
leading  from  each  individual  grape  may  represent  the  small 
duct  which  carries  the  milk  on  to  the  larger  ducts.  The  main 
stems  of  the  bunch  may  represent  the  larger  ducts  that  enter 
into  the  milk-reservoir.  The  air  which  everywhere  fills  the 
openings  or  interstices  of  the  various  parts  of  the  bunch  of 
grapes  may  be  likened  to  the  fibrous  fatty  tissue  between  the 
alveoli  and  the  lobules  of  the  gland. 

Theories  of  Milk  Secretion. — Although  the  theories  of  milk 


26  BUTTER-MAKING. 

secretion  have  been  studied  considerably,  many  things  in  this 
connection  are  not  well  understood.  Previous  to  the  year 
1840  it  was  thought  that  the  only  function  of  the  milk-gland 
was  to  filter  the  milk  as  it  transuded  from  the  blood.  It  was 
supposed  that  the  quality  and  quantity  of  milk  depended 
entirely  upon  the  food.  The  theory  has  also  been  advanced 
that  the  major  portion  of  the  milk  constituents  was  a  decom- 
position of  the  product  of  the  lymph  bodies  of  the  blood.  It 
was  believed  that  the  lymph  bodies  were  a  source  of  nourish- 
ment to  the  foetus,  and  that  the  calf  received  its  nourishment 
from  the  same  source  after  it  was  born  as  it  did  previous  to 
birth.  It  was  supposed  that  after  the  birth  of  the  calf  the 
opening  on  the  uterus  through  which  the  food  was  supplied 
was  closed,  and  that  a  new  opening  was  formed  in  the  milk- 
gland.  These  two  theories  have  now  been  practically  over- 
thrown. It  has  been  demonstrated  that  the  major  portion  of 
the  milk  is  formed  within  the  milk-gland.  The  fat,  casein, 
milk-sugar,  and  part  of  the  albumen  are  supposed  to  be  formed 
in  the  udder.  This  conclusion  is  substantiated  by  the  fact 
that  these  substances  do  not  appear  in  the  blood,  at  least  not 
to  such  an  extent  as  to  warrant  the  assumption  that  they  are 
not  manufactured  in  the  cow's  udder.  The  total  amount  of 
fat  in  the  blood  of  the  cow  would  not  equal  the  fat  in  the  milk 
from  one  milking. 

By  some  it  is  maintained  that  the  substances  in  milk  which 
are  found  in  solution  may  be  transuded  directly  from  the 
blood.  Here  again  milk-sugar  is  found  to  be  in  perfect  solu- 
tion in  the  milk,  but  this  substance  can  be  found  nowhere  in 
nature  besides  in  milk.  It  is  not  present  in  the  blood  of  the 
animal,  consequently  it  must  be  manufactured  within  the 
gland  itself.  The  water  of  milk,  and  the  ash  constituents  which 
are  in  solution,  are  probably  transuded  directly  from  the  blood. 
No  attempts  have  been  made  to  determine  definitely  ho\v 
casein  and  albumen  are  formed  within  the  gland. 

The  theory  advanced  for  the  formation  of  fat  is,  that  the 
epithelial  cells  break  down  and  form  f^t.  When  the  breaking- 


MILK  SECRETION  27 

down  process  is  completed,  the  transformed  cells  appear  at 
the  opening  of  the  alveoli  in  the  form  of  distinct  fat-globules. 
This  is  supposed  to  be  the  origin  and  formation  of  fat-globules 
in  milk;  so  it  may  be  said  that  so  far  as  known  the  fat 
is  the  result  of  a  breaking  down  of  degenerated  epithelial  cells. 
Dr.  Bitting  asserts  that  the  formation  of  milk  solids  in  the 
cow's  udder  is  probably  due  to  a  metabolic  process  rather  than 


FIG.  3. — A  schematic  figure  showing  the  course  of  the  artery  leading  to  the 
mammary  gland  and  the  veins  returning  to  the  hfart.  The  light-colored 
lines  represent  arteries  and  the  dark-colored  lines  the  veins.  (From 
Bitting,  Twelfth  An.  Report,  Indiana.) 

to  a  degenerative.  Collier  found  that  a  cow  giving  a  normal 
amount  of  milk  would  secrete  about  136,000,000  fat-globules 
per  second.  He  also  suggests  that  a  cow  secretes  about  5 
pounds  of  milk  solids  per  day.  As  a  cow's  udder  weighs  only 
about  2|  pounds,  the  whole  udder  would  have  to  be  renewed 
twice  daily.  This  is  not  consistent  with  our  present  knowledge 
of  tissue  building. 


28  BUTTER-MAKING. 

The  chief  incentive  to  milk  secretion  is  maternity.  As  soon 
as  the  young  mammalia  is  born  the  blood  which  went  to  the 
uterus  to  supply  the  calf  is  turned  towards  the  udder  instead. 
As  soon  as  this  current  of  blood  begins  to  flow,  all  of  the  blood- 
vessels and  capillaries  in  the  cow's  udder  swell.  This  causes 
the  minute  blood-vessels  or  capillaries  which  form  a  network 
in  the  walls  of  the  alveoli  to  swell.  This  swelling  stimulates 
the  epithelial  cells  to  activity. 

Conditions  Affecting  Secretion  of  Milk.  —  There  are  a 
great  many  conditions  which  affect  the  milking  capacity  of  a 
cow.  These  conditions  may  be  conveniently  grouped  into  two 
classes  according  to  their  causes:  (1)  conditions  which  are  con- 
trolled largely  by  man,  and  (2)  conditions  which  are  inherent 
to  the  cow, 

1.  Some  of  the  chief  conditions  which  reduce  the  secretion 
of  milk  and  are  largely  controlled  by  man  are:   improper  care 
and  treatment  of  the  cow,  lack  of  proper  food,  incomplete  and 
improper    milking,    irregularity,    and    long    periods    between 
milkings.     Pregnancy,  nervousness,  or  excitement  of  any  kind 
affect    the    proper   working   of   the   milk-glands   considerably. 
These  latter  causes,  however,  are  not  always  controlled  by  man. 

2.  Without  denying  the  influence  of  those  conditions  men- 
tioned  above,   the  conditions  which  chiefly  affect   the  milk- 
secreting  capacity  are  inherent.     It  does  not  matter  how  much 
good  care  and  food  a  cow  receives,  if  she  does  not  possess 
these  inherent  necessary  qualities.     As  was  mentioned  before, 
the  milk-secreting  capacity  depends  upon  the  number  of  gland- 
lobules,  upon  the  amount  of  blood  which  is  supplied  to  these  secre- 
tory parts,  and  upon  the  capacity  of  the  cow  to  digest  and  assimilate 
food. 

The  number  of  gland-lobules  is  believed  to  increase  until 
the  cow  is  about  seven  years  old.  The  milk-secreting  glands 
are  present  only  in  a  rudimentary  form,  until  the  cow  has  had 
her  first  calf,  or  is  well  advanced  in  the  first  stage  of  pregnancy. 
The  gland-lobules  then  increase  in  number  up  to  the  age  of 
about  seven.  The  relative  number  of  lobules  in  the  cow's 


MILK  SECRETION.  29 

udder  can  only  be  approximately  ascertained.  The  size  of 
the  udder  in  some  measure  indicates  this.  A  cow  with  a  large 
flexible  udder  is  usually  a  good  milker,  due  to  the  fact  that  a 
large  udder  usually  contains  a  large  number  of  gland-lobules. 

The  amount  of  blood  which  is  turned  through  the  cow's 
udder  to  supply  the  milk-secreting  cells  may  approximately 
be  ascertained  by  the  size  of  the  blood  vessels.  The  blood 
enters  the  udder  from  the  heart  near  the  region  of  the  hips. 
It  then  passes  down  through  the  udder,  along  the  abdomen 
just  beneath  the  skin,  until  it  reaches  about  midway  between 
the  flank  and  the  girth.  At  this  place  it  penetrates  the  abdom- 
inal wall  and  enters  the  thorax.  The  place  at  which  the  blood 
penetrates  the  abdominal  wall  may  be  felt  with  the  finger. 
It  is  supposed  that  the  size  of  this  hole  is  in  some  measure 
indicative  of  the  milk-producing  capacity  of  the  cow.  This 
opening  in  the  abdominal  wall  is  called  the  milk-hole  or  milk- 
fountain.  Large  irregular  veins  are  considered  a  much  better 
indication  of  good  milking  properties  than  small  straight  veins. 

The  formation  of  gland-lobules  is  entirely  inherent  in  the 
cow.  The  only  way  that  these  may  be  increased  is  through 
selection  and  breeding.  The  amount  of  blood  which  passes 
through  the  cow's  udder  is  also  largely  inherent,  although 
this  may  in  a  small  measure  be  affected  by  the  amount  and 
quality  of  food  given  to  the  cow.  It  should  at  all  times  be 
remembered  that  a  cow  is  not  a  mere  receptacle  into  which 
so  much  food  can  be  introduced,  and  so  much  milk  drawn 
from  the  other  end.  After  giving  due  credit  for  the  influence 
of  all  other  conditions,  we  must  still  recognize  that  the  inherent 
conditions  affecting  the  secretion  of  milk  are  the  most  important. 

External  Appearance  of  the  Udder. — A  cow's  udder  should 
be  well  and  symmetrically  formed.  It  should  be  square,  wide, 
extend  well  along  the  abdomen  of  the  cow,  and  back  up  between 
the  thighs.  When  the  udder  is  empty  it  should  be  soft  and 
flexible.  The  teats  should  be  medium  large,  should  be  placed 
well  apart,  and  should  point  downwards. 
There  should  be  little  or  no  depression  in  the  udder  between 


30  BUTTER-MAKING. 

the  teats;  that  is,  each  quarter  should  not  appear  distinct 
and  separate  when  viewed  from  the  exterior. 

The  cow's  udder  should  be  covered  with  fine  soft,  downy 
hair.  A  light  golden  yellow  is  said  to  be  indicative  of  a  good 
quality  of  milk. 

A  firm,  fleshy  udder  is  undesirable.  In  the  first  place,  it  is 
not  indicative  of  good  milking  qualities,  and,  secondly,  such 
an  udder  is  predisposed  to  inflammatory  diseases. 

Milk-fever.  —  This  is  a  common  disease  in  fresh  cows. 
It  is  due  to  a  congested  condition  of  the  cow's  udder.  The 
decomposition  products  of  the  colostrum  milk  in  the  udder 
are  absorbed  by  the  blood,  and  produce  the  characteristic 
symptoms  of  milk-fever.  Dr.  Peters,  of  the  Nebraska  Experi- 
ment Station,  says  that  a  good  and  simple  remedy  for  a  diseased 
udder  is  to  pump  it  full  of  air.  This  can  be  accomplished 
with  an  ordinary  bicycle  pump.  After  some  air  has  been 
pumped  in,  then  the  cow's  udder  should  be  worked  or  massaged 
with  the  hand  so  as  to  cause  the  air  to  pass  through  the  quarter. 
He  claims  that  the  udder  can  thus  be  restored  to  its  normal 
condition  very  quickly,  thereby  preventing  and  even  curing 
milk-fever.  In  case  the  udder  is  caked  very  badly,  apply  a 
hot  poultice.  Small  five-  or  ten-pound  bags  filled  with  bran 
and  kept  hot  is  a  good  substance  to  use.  A  compress 
is  also  used.  This  consists  simply  of  using  a  piece  of  heavy 
cloth.  Put  it  on  so  that  it  lifts  up  the  entire  udder,  and  tie 
it  over  the  back  of  the  cow.  Straw  should  be  put  underneath 
it  on  the  back  so  that  the  cord  does  not  injure  the  animal. 


CHAPTER  III. 
PROPERTIES  OF  MILK. 

Color. — The  color  of  normal  milk  ranges  between  bluish 
white  and  golden  yellow,  according  to  breeds,  foods,  and  sea- 
sons of  the  year.  The  milk  yielded  by  Jersey  cows  generally 
is  more  yellow,  due  chiefly  to  the  larger  amount  of  fat  which 
it  contains.  Holstein  cows  yield  milk  of  a  whiter  color.  Foods 
such  as  grass  and  certain  roots  (mangles  and  carrots)  have 
the  power  of  giving  to  milk  a  higher  color.  As  has  been  pre- 
viously mentioned,  the  coloring  substance  in  milk  has  been 
named  lactochrome,  and  so  far  as  known  is  associated  with 
the  palmitin  fat. 

Flavor. — Milk  has  a  sweet  flavor,  and  a  faint  odor.  Fresh 
milk  has  a  peculiar  cowy  taste  and  odor,  which  pass  off  when 
exposed  to  the  air.  The  flavor  is  affected  by  foods  and  con- 
ditions of  the  cow,  as  mentioned  under  "  Abnormal  Milk." 

Opacity  of  Milk. — Milk  is  opaque,  except  when  seen  in 
very  thin  layers;  then  it  is  slightly  transparent.  The  opacity 
of  milk  is  due  to  the  presence  of  the  fat  and  nitrogenous  mat- 
ter. When  these  substances  are  filtered  away  on  a  fine  clay 
filter  (the  Chamberland),  the  filtrate  which  passes  through 
is  clear  and  transparent.  It  has  been  maintained  that  the 
fat  in  milk  is  the  chief  cause  of  its  opacity,  and  that  the  per- 
centage of  fat  could  be  determined  according  to  the  degree 
of  opacity  and  transparency  of  milk  with  an  instrument  named 
pioscope;  but  it  was  soon  found  out  that  the  size  of  the 
fat-globules,  as  well  as  the  number,  had  considerable  influence 
upon  the  degree  of  opacity  of  milk.  For  that  reason,  this 
method  of  determining  the  amount  of  fat  in  milk  was  not 

31 


32  BUTTER-MAKING. 

reliable.  The  fat-glpbules  themselves  are  said  to  be  almost 
transparent,  yet  the  color  and  opacity  of  milk  is  largely  due 
to  their  presence.  This  characteristic  may  perhaps  be  explained 
by  assuming  that  the  fat-globules  in  milk  deflect  the  light 
instead  of  allowing  it  to  pass  through  them. 

The  opacity  of  milk,  after  the  fat  has  been  removed,  is 
due  to  the  presence  of  nitrogeneous  matter.  After  the  fat 
has  been  removed  from  the  milk,  the  milk  still  continues  to 
be  opaque.  When  the  albuminoid  matter  has  been  removed 
and  filtered  off  the  filtrate  becomes  clear  and  transparent. 

Chemical  Reaction  of  Milk. — Milk  when  fresh  shows  an 
amphoteric  reaction,  which  means  that  it  exhibits  both  an 
alkaline  and  an  acid  reaction  when  tested  with  litmus  paper. 
It  turns  blue  litmus  paper  red,  and  red  litmus  paper  blue.  This 
peculiar  behavior  of  milk  is  said  to  be  due  to  the  caseous  matter 
in  the  milk,  which  itself  has  an  acid  reaction,  but  the  remainder 
of  the  serum  has  a  slight  alkaline  reaction.  By  testing  the 
reaction  of  fresh  milk  with  a  tenth  normal  alkali  solution, 
and  using  phenolphthalein  as  an  indicator,  it  will  be  found 
to  give  an  acid  reaction.  After  standing,  milk  soon  becomes  dis- 
tinctly acid,  which  is  due  to  a  change  of  the  milk-sugar  into 
acids,  chiefly  lactic  acid,  through  the  action  of  micro-organisms. 
Richmond  maintains  that  the  amphoteric  reaction  of  milk 
has  acquired  a  false  importance,  as  he  believes  that  the  neu- 
trality, as  measured  by  the  action  of  litmus  paper,  is  not  chemi- 
cal neutrality. 

Specific  Gravity  of  Milk. — By  specific  gravity  of  milk  we 
mean  the  weight  of  the  milk  as  compared  to  that  of  an  equal 
volume  of  water  at  the  same  temperature.  If  a  certain  volume 
of  water  weighs  1000  pounds,  an  equal  volume  of  milk  at  the 
same  temperature  and  under  the  same  conditions,  will  wreigh 
about  1032  pounds.  Reducing  the  figure  to  a  basis  of  1,  as  is 
always  done,  the  comparison  between  the  two  equal  volumes 
of  water  and  milk  will  be  1  and  1.032.  This  latter  figure 
represents  the  average  specific  gravity  of  normal  milk. 

It  can  be  readily  seen  that  the  correct  specific  gravity  can 


PROPERTIES  OF  MILK.  33 

only  be  obtained  at  one  given  temperature,  for,  as  the  tempera- 
ture of  the  substance  becomes  higher,  the  density  of  it  grows  less, 
and  consequently  the  specific  gravity  will  be  less.  The  tempera- 
ture at  which  the  lactometers  are  standardized  is  60°  F. 

The  variations  in  the  specific  gravity  of  milk  will  also  vary 
according  to  the  relative  variation  in  amounts  of  the  different 
components  of  milk.  If  a  sample  of  milk  is  rich  in  solids  not 
fat,  as,  for  instance,  skimmed  milk,  the  specific  gravity  will  be 
high  and  usually  between  1.033  and  1.037.  If  the  sample  of 
milk  is  rich  in  fat,  as,  for  instance,  in  cream,  the  specific  gravity 
will  be  less. 

By  adding  water  to  milk,  the  specific  gravity  of  it  is  lessened. 
Owing  to  this  fact  it  was  first  thought  that  adulteration  of  milk 
with  water  could  be  detected  by  testing  its  specific  gravity. 
But  this  method  was  soon  found  to  be  erroneous,  as  it  is 
possible  to  take  cream  away  and  add  water  in  such  a  proportion 
as  not  to  alter  the  specific  gravity  of  the  sample.  A  low  specific 
gravity  of  milk  may,  however,  cause  the  suspicion  that  the  milk 
has  been  adulterated,  and  the  test  for  water  adulteration  can 
be  supplemented  by  testing  it  for  fat. 

As  has  been  mentioned  before,  the  lactometer  reading  should 
be  taken  at  60°  F.  If  the  temperature  of  milk  is  above  or 
below,  corrections  must  be  made.  The  amount  of  correction 
which  will  give  approximate  results  is  .1  of  a  degree  added  to 
the  lactometer  reading  for  every  degree  Fahrenheit  of  tempera- 
ture the  milk  is  above  60°  F.,  and  also  .1  of  a  degree  subtracted 
from  the  lactometer  reading  for  every  degree  of  temperature  the 
milk  is  below  60°  F.  The  temperature  of  milk  when  tested  for 
lactometer  reading  should  never  go  any  lower  than  10°  below 
60°,  nor  any  higher  than  10°  above  60°.  This  would  leave  the 
range  of  temperature  between  50°  and  70°  F. 

In  chemical  laboratories,  the  specific  gravity  of  milk  is 
usually  determined  by  the  use  of  a  picnometer. 

In  practice  there  are  three  instruments  in  general  use  for 
determination  of  lactometer  reading,  or  specific  gravity,  viz.: 
Quevenne  lactometer,  New  York  Board  of  Health  lactometer 


34 


BUTTER-MAKING. 


and  the  ordinary  hydrometer.  The  Quevenne  lactometer  is  the 
one  that  is  used  chiefly  in  creameries.  The  graduation  of  each 
one  of  them  is  given  in  the  accompanying  diagram.  It  may  be 


i.ooo 

n 

10- 

1.00S- 

20- 

i.oio- 

1.016 

50- 

15- 

eo 

1.020- 

'0- 

,o. 

JO- 

1.025- 

n. 

CO 

100 

___—  —  ^»— 

1.030 

Zti 

110 

1.035 

120' 

35- 

40 

S 

4 

0 

L 

•'  S  "  Specific  Gravity  Scale.. 
"  N  "  New  York  State. 
"  Q"  Quevenne, 
FIG.  4. — Comparative  graduation  of  lactometer  stems. 

seen  from  the  figures  that  in  order  to  change  the  Quevenne 
lactometer  reading  into  specific  gravity,  all  that  is  necessary  is 
to  add  1000  and  divide  the  sum  by  1000.  In  order  to  change  the 


PROPERTIES  OF  MILK.  35 

specific  gravity  into  lactometer  reading  the  reverse  process  will 
give  correct  results. 

The  hydrometer  gives  the  specific  gravity  directly.  The 
Board  of  Health  lactometer  has  a  special  graduation.  In 
devising  this  lactometer  it  was  thought  that  1.029  was  the 
minimum  specific  gravity  of  unadulterated  milk.  The  scale  on 
this  lactometer  was  made  from  zero  to  120;  zero  marking  the 
point  which  represents  the  specific  gravity  of  water,  namely,  1. 
100  is  the  point  which  is  assumed  to  represent  the  least  specific 
gravity  of  milk  1.029.  If  the  specific  gravity  of  a  certain 
sample  of  milk  fell  to  90,  it  indicated  that  there  was  10%  of 
water  present.  If  it  fell  to  80,  it  indicated  that  there  was  20% 
of  water,  etc. 

In  order  to  calculate  the  total  solids,  and  solids  not  fat,  of 
milk,  it  is  necessary  to  know  the  lactometer  reading,  and  the 
percentage  of  fat  content.  Knowing  these  factors,  by  the  use 
of  the  following  formula  given  by  Farrington  and  Woll,  and 
deduced  from  Fleischmann's  work,  the  total  solids,  and  solids 
not  fat,  can  be  found: 

Solids  not  fat=  |  lactxreadmg  +  .2  times  the  fat. 
Total  solids    =  f at  +  solids  not  fat. 

Natural  Separation  of  Milk  and  Cream. — When  milk  is 
allowed  to  stand  quietly  for  a  short  time,  a  layer  having  a  rich- 
yellow  color  comes  to  the  surface.  This  is  the  cream,  and 
contains  most  of  the  fat.  This  separation  is  due  chiefly  to  the 
difference  in  weight,  or  specific  gravity,  of  the  fat-globules  and 
the  serum.  The  force  which  acts  upon  the  globule  of  fat  is  the 
difference  in  weight  between  the  fat-globule  and  the  serum 
which  it  displaces,  minus  the  resistance  force  with  which  it 
meets  in  its  upward  passage.  In  milk  with  a  high  degree  of 
viscosity  this  force  is  great.  In  milk  of  a  limp  and  liquid 
consistency  this  force  is  smaller.  By  adding  water  the  vis- 
cosity of  milk  is  reduced  considerably,  and  the  specific  gravity 
of  the  serum  is  also  decreased.  But  the  effect  of  the  added 
water  upon  the  viscosity  is  greater  than  the  effect  the  water  has 


36 


BUTTER-MAKING. 


upon  the  specific  gravity  of  the  serum;  hence,  by  adding  water 
to  milk,  the  resistant  force  is  decreased  to  such  an  extent  as  to 
get  a  more  rapid  and  more  efficient  separation  of  the  fat.  The 
water  dilution  separators  are  based  upon  this  principle.  In 
normal  milk,  the  amount  of  fat  left  in  the  skimmed  milk  by 
natural  creaming  is  about  .4%.  The  fat  which  is  left  in  this 
skimmed  milk  is  largely  composed  of  very  small  globules. 
This  is  due  to  the  fact  that  the  resistant  force  of  these  small 
globules  is  equal  to  or  greater  than  the  buoyant  force  acting 
upon  them. 


FIG.  5. — Standardized  milk.     Showing  the  amount  of  cream  on  milk  con- 
taining the  designated  per  cent  of  butter-fat.     (From  Bui.  92,  111.) 

This  completeness  of  natural  skimming  is  to  a  certain  extent 
based  upon  the  mathematical  law  which  is  stated  as  follows: 
"The  surfaces  of  two  spheres  are  to  each  other  as  the  squares  of 
their  diameters,  and  their  cubical  contents  are  to  each  other 
as  the  cubes  of  their  diameters."  The  larger  the  globules  are, 
the  greater  the  surface  is,  and  the  greater  the  resisting  force  to 
which  they  are  subjected.  From  the  law  stated  it  can  be  seen 
that  as  the  size  of  the  globule  increases,  the  cubical  content 
increases  more  rapidly  than  the  surface.  If  a  fat-globule  were 
split  up  into  smaller  ones,  there  would  be  more  surface  exposed 


of 

ALr 

PROPERTIES  OF  MILK.  37 

to  the  serum  than  was  the  case  while  the  fat  was  present  in 
one  globule. 

For  illustration,  take  two  globules  of  fat  having  a  diameter  of 
4  and  2  inches  respectively.  The  squares  would  be  16  inches 
and  4  inches  respectively;  their  cubes  would  be  64  inches  and 
8  inches  respectively.  It  will  thus  be  seen,  according  to  the 
law  quoted  above,  that  the  larger  globule  has  a  surface  only  four 
times  as  great  as  that  of  the  smaller  one ;  but  the  cubical  content 
of  the  larger  globule  is  eight  times  that  of  the  smaller  one.  This 
illustrates  why  the  large  globules  rise  in  cream  quicker  than 
the  small  ones.  In  this  particular  instance  the  upward  force 
the  larger  globule  is  subjected  to  is  eight  times  greater  than 
that  of  the  smaller  one,  while  the  resistance  force  is  only  four 
times  as  great  as  that  of  the  small  one. 

Adhesion  of  Milk. — Normal  sweet  milk  adheres  to  wood, 
glass,  and  metals  to  a  greater  extent  than  does  water.  Whole 
milk  has  greater  adhesive  properties  than  skimmed  milk. 
A  paper  moistened  with  milk  or  cream  makes  a  label  that 
will  stick  to  any  dry  object;  the  same  paper  moistened  with 
skimmed  milk  has  less  adhesive  power.  The  adhesive  prop- 
erties of  milk  are  also  due  to  the  condition  of  the  nitrogenous 
matter.  This  fact  is  made  use  of  in  painting  and  whitewashing. 
Slacked  lime,  when  mixed  with  buttermilk,  or  milk  of  any 
kind,  gives  a  whitewash  which  will  remain  on  objects  much 
longer  than  that  made  by  mixing  with  water. 

Viscosity  of  Milk. — Milk  is  more  viscous  than  water.  The 
degree  of  viscosity  of  fresh  milk  varies  chiefly  with  the  tem- 
perature and  fat  content.  So  far  as  understood,  the  lower 
the  temperature,  the  greater  the  viscosity.  Development  of 
acid,  and  high  temperature  lessens  the  viscosity  of  milk.  Pas- 
teurized milk  or  cream  is  less  viscous  than  the  same  milk  or 
cream  unpasteurized.  This  lack  of  body  can  again  be  restored 
by  adding  a  little  viscogen,  as  recommended  by  Babcock 
and  Russell.  It  is  advisable  not  to  use  it,  however,  as  it  does 
not  add  materially  to  the  nutritive  value  of  milk.  It  merely 
restores  the  body. 


38  BUTTER-MAKING. 

The  great  viscosity  of  thick  and  cold  cream  has  been 
encountered  by  most  butter-makers  when  attempts  have 
been  made  to  churn  cream  under  such  conditions.  It  adheres 
to  the  inside  of  the  churn  and  does  not  agitate.  It  simply 
rotates  with  the  churn.  Cream  that  is  cold  and  thick 
whips  more  easily  than  thin  and  warm  cream.  The  viscosity 
is  so  great  that  the  air  incorporated  cannot  escape  so  easily. 
In  ice-cream  making,  a  greater  yield  is  obtained  by  using 
cold  and  thick  cream.  The  air,  when  once  incorporated, 
cannot  easily  escape,  owing  to  the  great  viscosity  of  such 
cream. 

Specific  Heat  of  Milk. — The  specific  heat  of  milk  is  less 
than  that  of  water;  that  is,  it  requires  less  heat  to  warm  a 
definite  amount  of  milk  to  a  certain  temperature  than  it  does 
to  heat  the  same  quantity  of  water  to  the  same  temperature. 
It  also  takes  less  ice  to  cool  the  same  volume  of  milk  to  a  cer- 
tain temperature  than  it  does  to  cool  the  same  quantity  of 
wrater  to  the  same  temperature.  The  specific  heat  of  milk 
is,  according  to  Fjord,  .94.  The  specific  heat  of  cream  is 
about  .7.  It  varies  according  to  the  percentage  of  fat  in  the 
cream.  The  specific  heat  of  butter  is  about  .4.  From  these 
figures  it  will  be  seen  that  it  takes  less  heat  to  warm  milk, 
cream,  and  butter,  and  less  cold  to  cool  the  same  substances, 
than  it  does  to  heat  and  cool  water;  but  it  takes  a  longer  time 
to  heat  or  to  cool  milk,  cream,  and  butter;  that  is,  the  milk, 
cream,  and  butter  are  not  as  rapid  conductors  of  heat  and 
cold  as  is  water. 

The  maximum  density  of  milk  is  not,  like  vater,  at  4°  C. 
but  at  about  .3°  C.  The  boiling-point  of  milk  is  a  trifle  higher 
and  the  freezing-point  a  trifle  lower  than  that  of  water. 

Effect  of  High  Heating  (180°  and  above)  on  Properties  of 
Milk. — The  chief  effects  of  heat  upon  milk  may  be  summarized 
in  the  following  headings : 

(1)  It  destroys  nearly  all  germs  present  in  the  milk. 

(2)  It  diminishes  the  viscosity,  or  body. 

(3)  It  drives  off  gases 


PROPERTIES  OF  MILK  39 

(4)  It  imparts  a  cooked  taste  (especially  if  not  heated  and 
cooled  properly). 

(5)  It  precipitates  some  of  the  albuminoids   and  ash  con- 
stituents. 

(6)  It  destroys  the  properties  of  enzymes  present  in  milk. 

(7)  It  divides  or  splits  up  the  fat  globules. 

(8)  It  caramelizes  some  of  the  sugar. 

1.  Destroys  Nearly  All  Germs. — Heating    milk    to  a  tem- 
perature of  about  380°  F.  for  ten  minutes  destroys  most  of 
the   germs   present  in   milk.     This  is   the   temperature   used 
chiefly  in  creameries  for  pasteurization.     The  details  concern- 
ing1 the  different  effects  of  temperature  upon  growth  of  germs 
properly  comes  under  the  heading  of  bacteriology,  and  will 
be  referred  to  more  in  detail  in  the   chapter  on  "  Bacteria  in 
Milk." 

2.  Diminishes   the  Viscosity,    or   Body. — Heating   milk    or 
cream  diminishes  the  viscosity  of  these  substances;     that  is, 
the  body  or  consistency  is  lessened;   and  in  cities  where  milk 
or  cream  is  sold  directly  to  consumers,  heated  milk  appears 
as  if  it  had  been  adulterated.     This  diminution  in  the  body 
is  claimed  to  be  due  to  a  breaking  up  of  the  fat-globules  and 
the  caseous  matter.     The  chemical  union  of  some  of  the  cal- 
cium salts  and  the  casein  is  altered  or  destroyed. 

The  consistency  of  milk  or  cream  can  be  'restored  by  adding 
a  substance  named  viscogen.  Russell  and  Babcock*  advise 
this  method  of  overcoming  the  apparent  defect  caused  by 
heating.  It  consists  of  making  a  strong  solution  of  cane-sugar 
and  mixing  it  with  freshly  slacked  lime.  This  mixture  is 
allowed  to  stand,  and  the  clear  solution  coming  to  the  top 
is  the  viscogen,  which,  when  drawn  off  and  used  in  the  pro- 
portion of  one  part  of  viscogen  to  from  100  to  150  parts  of 
cream,  restores  the  body  of  cream  or  milk.  This  is  due  to 
the  fact  that  viscogen  causes  the  fat-globules  to  cluster  together 
again,  and  the  lime  in  the  viscogen  may  combine  with  the 


*  Bulletin  No.  54,  Wisconsin. 


40  BUTTER-MAKING. 

nitrogenous  constituents  in  such  a  way  as  to  aid  in  the  resto- 
ration of  the  body  of  the  cream  or  milk. 

Nearly  all  dairy  laws  forbid  the  addition  of  any  foreign 
substances  to  milk  or  cream.  If  viscogen  is  added,  Babcock 
and  Russell  suggest  to  name  it  visco-milk,  visco-cream,  etc. 
When  this  modification  is  made,  then  no  objection  can  be 
raised  to  its  legitimate  use. 


FIG.  6. — Microscopic  appearance  of  milk,  showing  natural  grouping  of  the 
fat-globules.  Single  group  in  circle,  highly  magnified.  (From  Bui  64, 
Wis.^ 

3.  Drives    off    Gases. — When  milk  is   heated,    taints,   and 
gases  of  different  kinds  pass  off  to  some  extent.     This  is  facili- 
tated by  heating  and  stirring  in  an  open  vessel.     Many  of 
these  gases  also  escape  when  rnilk  is  aerated   and  cooled  in  a 
pure  atmosphere. 

4.  Imparts  a  Cooked  Taste. — When  milk  is  heated  to  160°  F. 
or  above,  it  assumes  a  distinctly  cooked  taste,  which  makes  it 
disagreeable  as  a  food  for  many  people.     On  this  account, 
milk  for  city  supply    in  America    is    generally    not    heated. 
In  a  few  cities  where  milk  is  consumed  directly,  heating  and 
cooling    (pasteurization)    has    been   generally    introduced.     It 
is  said   that   people   can  become  accustomed   to   this  cooked 
flavor  and  acquire  a  liking  for  it.    When  milk  is   not  heated 
higher  than  180°  F.,  nor  exposed  to  the  heat  very   long,  and 


PROPERTIES  OF  MILK.  41 

cooled  quickly,  the  cooked  taste  can  be  greatly  reduced  and 
almost  entirely  avoided.  Where  heating  or  pasteurization 
of  cream  has  been  adopted,  as  in  some  creameries,  the  pre- 
vention of  this  cooked  flavor  in  the  butter  is  of  vital  importance. 
The  reason  why  this  cooked  flavor  forms  in  milk  when 
heated  is  not  well  understood.  It  is  supposed  to  be  due  to 
the  effect  which  heat  has  upon  the  nitrogeneous  constituents 
of  milk. 

5.  Precipitates    Albuminoid    and    Ash    Constituents. — When 
milk  is  heated,  there  is  a  tendency  for  the  soluble  salts  and  a 
portion  of  the  albuminoids  to  be  thrown  down,  or  changed  into 
an  insoluble  form. 

The  higher  the  milk  is  heated,  the  greater  is  this  tendency. 
By  subjecting  a  sample  of  milk  in  a  flask  to  intense  heat,  and  then 
allowing  it  to  stand,  a  fine  white  sediment  will  be  deposited  on 
the  bottom.  This  is  believed  to  be  minerals  precipitated  from 
the  milk. 

When  milk  has  been  heated  to  about  170°  F.,  and  cooled, 
rennet  is  unable  to  precipitate  the  curd  in  a  normal  way.  The 
curd  resulting  from  adding  rennet  to  pasteurized  milk  is  floccu- 
lent  in  nature.  It  does  not  assume  that  smooth  and  even 
texture  that  curd  from  raw  milk  has  when  precipitated  with 
rennet.  This  abnormal  behavior  of  pasteurized  milk  towards 
rennet  can  be  reestablished  by  adding  a  small  quantity  of 
calcium  chloride  (CaCl).  Whether  this  would  effect  the 
quality  of  cheese  materially  has  not  yet  been  determined 
definitely.  According  to  G.  Fascetti,*  if  pasteurized  milk  is 
used  for  cheese-making,  the  cheese  ripens  more  slowly  than 
when  made  from  raw  milk.  The  same  investigator  also  claims 
that  a  larger  quantity  of  cheese  is  obtained  per  100  parts  of  milk 
when  pasteurized  milk  is  used. 

6.  Destroys  Properties  of  Enzymes. — As  was  mentioned  in 
the  composition  of  milk  there  is  a  substance  normal  to  milk 
named  galactase.     This  is  an  enzyme.     By  heating    milk  to 

*  Exper.  Sta.  Record,  Vol.  15,  No.  10,  1904. 


42  BUTTER-MAKING. 

about  175°  F.  the  properties  of  the  enzyme  are  destroyed  Owing 
to  this  it  is  easy  to  detect  whether  a  certain  sample  of  milk  has 
been  pasteurized  or  not.  Galactase  is  present  in  so  small  a 
quantity  that  it  could  not  be  determined  in  milk  quantitatively. 
It  must  be  detected  in  a  qualitative  way. 

The  test  used  and  invented  by  Storch,  of  Copenhagen, 
Denmark,  is  to  put  a  small  quantity  of  milk  in  a  test-tube,  add  to 
it  a  small  quantity  of  a  weak  solution  (2%)  of  hydrogen  peroxide 
(H202),  a  small  quantity  of  potassium  iodide,  and  a  little  starch 
solution.  The  whole  mixture  is  then  shaken.  If  the  mixture  does 
not  change  in  color,  it  has  been  heated  to  at  least  170°  F.  If  it 
turns  blue,  it  has  not  been  heated  to  a  sufficiently  high  tempera- 
ture to  destroy  the  properties  of  the  enzyme  present  in  the  milk. 
Another  test  which  can  be  used  in  distinguishing  raw  milk  from 
scalded  or  boiled  milk  is  to  take  10  cubic  centimeters  of  the  milk 
to  be  tested,  add  1%  of  recently  prepared  aqueous  solution  of 
"Ortol,"  and  then  one  or  two  drops  of  hydrogen  peroxide.  If 
the  milk  has  not  been  heated,  a  vivid  red  color  is  produced. 
Heated  milk  shows  no  effect. 

7.  Divides  the  Fat-globules.  —  The  fat-globules  in  normal 
milk  are  grouped  in  minute  clusters.     When   milk  is  heated, 
these  clusters  break  up,   and  each  globule    exists    more    or 
less    independently.     When    heated    to    an    excessively    high 
temperature,  and  exposed  to  this  temperature  very  long,   the 
fat-globules  tend  to  run  together.     This  can  be  proved  by 
heating  milk  in  an  open  vat  for  about  half  an  hour.     A  small 
amount  of  yellow  fat  will  then  be  seen  floating  on  the  top. 

8.  Caramelizes  the   Sugar. — The  brownish  color  which  the 
milk  assumes  when  it  is  heated  excessively  is  due  to  a  change 
which  the  milk-sugar  undergoes.     Fleischmann  claims  that  the 
sugar  begins  to  change  into  a  substance  known  as  lacto-caramel 
at  a  temperature  of   160°  F.    This  change,  however,  is  not 
pronounced  enough  to  be  apparent  in  the  color,  unless  the  milk 
is  heated  a  long  time.     The  higher  the  temperature  is,  and  the 
longer  it  is  exposed  to  the  heat,  the  more  pronounced  is  the 
change. 


PROPERTIES  OF  MILK.  43 

General  Remarks. — While  all  of  the  above  changes  have 
been  found  by  investigators  to  take  place  when  milk  is  heated, 
they  can,  in  a  measure,  be  avoided,  if  special  precautions  are 
taken  in  the  heating  and  cooling  of  milk  with  the  special, 
recently  unproved  forms  of  apparatus  for  heating  and  cooling 
milk.  The  heating  to  160°  F.  can  be  accomplished  without 
changing  materially  the  chemical  or  physical  properties  of 
milk.*  Rapid  heating  and  rapid  cooling  seem  to  be  two  essen-^\ 
tials  in  order  to  prevent  changes  from  occurring  in  the  milk. 

*  Fjadon,  Koshe,  and  Hertel  in  Exp.  St.  Record,  Vol.  14,  No.  5. 


CHAPTER  IV. 

FERMENTS  IN  MILK. 

Definition. — The  changes  which  milk  undergoes  by  standing 
at  a  suitable  temperature  are  called  fermentations.  The 
causal  agents  are  called  ferments.  There  are  two  kinds  of 
ferments  in  milk;  viz.:  (1)  the  organized,  and  (2)  the  unorgan- 
ized. The  latter  includes  the  enzymes.  So  far  as  known,  only 
one  pre-existing  enzyme  is  found  in  milk.  This  one  was  dis- 
covered by  Russell  and  Babcock.  They  named  it  galactase. 
It  is  a  tryptic  ferment.  This  galactase  is  present  to  such  a 
small  extent  in  milk  that  it  exercises  very  little  influence  upon 
the  characteristics  of  milk.  If  the  milk  were  rendered  entirely 
sterile  or  free  from  organized  ferments,  the  fermentative  changes 
would  proceed  at  an  unusually  slow  rate.  The  galactase  has 
been  suggested  to  be  of  some  importance  to  the  butter-making 
industry.  The  properties  of  galactase,  like  those  of  any  other 
enzyme,  are  destroyed  by  heating  to  or  above  a  temperature  of 
about  175°  F. 

The  organized  ferments  are  by  far  the  most  important  to  the 
dairy  industry.  It  should  be  understood  in  this  connection 
that  the  organized  ferments  may  produce  unorganized  ferments, 
or  enzymes,  as  products,  but  these  produced  enzymes  do  not 
exist  in  milk,  like  galactase,  when  it  is  first  drawn  from  the  cow. 
The  organized  ferments  of  milk  consist  chiefly  of  bacteria. 
There  are  present  also  some  yeasts  and  molds. 

It  is  a  common  impression  that  bacteria  are  animals,  which 
is  incorrect.  Bacteria  are  minute  microscopical  plants,  belong- 
ing to  the  lowest  order  of  plants  in  the  vegetable  kingdom. 
Bacteria  differ  from  the  ordinary  plants  that  we  see,  in  that 
they  are  composed  of  a  single  cell  containing  protoplasm, 

44 


FERMENTS  IN  MILK.  45 

while  the  plants  that  we  see  in  every-day  life  are  aggregations 
of  cells.  Some  bacteria  are  motile,  while  others  are  not. 

Size  and  Shape  of  Bacteria. — In  size,  bacteria  are  the  smallest 
organisms  that  exist,  so  far  as  known.  The  size  varies  con- 
siderably. Russell  *  gives  the  average  diameter  as  S-Q^O- 
of  an  inch.  They  are  so  inconceivably  small  and  light  that 
nine  hundred  billions  of  them  would  only  weigh  ¥V  of  an 
ounce,  f 

Bacteria  also  vary  considerably  in  shape.  They  are  as  a 
rule  classed  into  three  groups:  (1)  The  bacillus  or  rod-shaped; 
C2)  The  coccus  or  ball-shaped;  (3)  The  spirillum  or  spiral- 
shaped  (like  a  corkscrew).  Some  types  of  bacteria  are  clas- 
sified according  to  the  way  in  which  they  adhere  to  each  other. 
For  instance,  when  two  cocci  occur  together  and  form  a  pair, 
they  are  called  diplococci,  when  bacteria  occur  in  chains, 
they  are  called  streptococci,  when  bacteria  appear  in  bunches 
they  are  called  staphylococci,  etc. 

FAVORABLE  CONDITIONS  FOR  BACTERIAL  GROWTH. 

Food. — Bacteria  are  like  other  plants  in  nature, — they  need 
food  for  their  existence.  However,  they  require  their  food  in 
solution.  Nitrogen,  carbon,  oxygen,  and  mineral  matter  are 
essentials  for  bacteria.  These  substances  are  furnished  in 
abundance  in  milk  from  casein,  albumen,  milk-sugar,  and  the 
mineral  salts.  Butter-fat  in  milk  is  said  to  be  of  little  value 
as  a  food  for  bacteria. 

Some  bacteria  prefer  a  substance  having  an  acid  reaction  in 
which  to  grow;  others  thrive  best  in  an  alkaline  medium. 
Most  bacteria,  however,  prefer  a  neutral  or  slightly  alkaline 
substance.  Darkness  is  essential  to  some  bacteria,  and  is 
preferred  by  the  majority  of  the  different  species.  Bright 
sunlight  is  a  very  effective  germicide.  It  is  fatal  to  all  species, 
so  far  as  known.  Some  germs  require  air  for  their  growth. 
These  are  called  aerobic.  Others  again  grow  only  in  the 

*  Dairy  Bacteriology.  t  Milk,  Its  Nature  and  Composition,  by  Aikman. 


46 


BUTTER-MAKING. 


absence  of  air.  These  are  called  anaerobic.  Some  grow  under 
either  or  both  conditions,  and  are  called  facultative  aerobic  or 
facultative  anaerobic. 

Temperature. — Favorable  temperature  is  essential  to  bac- 
terial growth.  Temperature  is;  indeed,  the  most  important 
means  by  which  the  growth  and  development  of  bacteria  can 
be  controlled.  The  range  of  temperature  at  which  bacterial 
growth  can  occur  may  be  placed  between  freezing-point  and 


'    .^vC^Y, <-V<  '^M'Vv'i  '/  •',  ,o, 

"~x!r'  xv/'"  Vi1  •''* "  v^\ i\/$\?v 


FIG.  7. — a,  single  bacterium;  b,  progeny  resulting  from  the  growth  of  a  bac- 
terium during  24  hours  in  milk  at  50°  F. ;  c,  progeny  of  a  bacterium 
during  24  hours  growth  in  milk  at  70°  F.  At  50°  F.  multiplication  was 
5-fold.  At  70°  F.  the  multiplication  was  750-fold.  (Bui.  26,  Storrs,  Conn.) 

a  little  above  110°  F.  The  growth  of  bacteria  at  these  ex- 
treme temperatures  is  very  slight.  Even  at  50°  F.  the  rate 
of  growth  is  very  slow.  According  to  experiments  conducted 
by  Dr.  Conn,  the  multiplication  of  bacteria  at  50°  F.  was  5- 
fold.  while  at  70°  F.  the  multiplication  was  750-fold.  The 
following  table  shows  the  number  of  bacteria  per  cubic  centi- 
meter in  milk  kept  at  different  temperatures:* 


No.  at 
Outset. 

In  12 
Hours 
at  50°. 

In  12 
Hours 
at  70°. 

In  50 
Hours 
at  50°. 

In  50  Hours 
or  at  Time  of 
Curdling 
at  70°. 

No.  of 
Hours  be- 
fore Curd- 
ling at  50° 

No.  of 
Hours  be- 
fore Curd- 
ling at  70°. 

46,000 
47,000 

50,000 

39,000 
44,800 

35,000 

249,500 
360,000 

800,000 

1,500,000 
127,500 

160,000 

512,000,000 
792,000,000 
36  hours 
2,560,000,000 
42  hours 

190 
289 

172 

56 
36 

42 

*  Bull.  26  Storr's  Stn.,  Conn 


FERMENTS  IN  MILK.  47 

All  bacteria  do  not  have  the  same  optimum  growing  tem- 
perature. Some  species  develop  most  rapidly  at  one  tempera- 
ture, while  other  species  prefer  a  different  temperature  for  the 
greatest  development.  It  is  on  this  account  that  certain  tem- 
peratures are  employed  in  ripening  of  starters  and  cream. 
According  to  researches  by  Conn,  Bacillus  lactis  aerogenes 
develops  very  rapidly  in  milk  at  95°  F.  It  produces  much  gas 
and  an  unpleasant  flavor  in  the  milk.  This  particular  species 
sours  milk  very  rapidly.  As  a-  rule,  milk  which  has  been  held 
at  this  high  temperature,  contains  a  preponderance  of  this 
undesirable  species  of  bacteria.  At  77°  F.  results  are  more 
uncertain.  The  species  of  bacteria  which  will  predominate  in 
milk  at  this  temperature  depends  in  large  measure  upon  the 
number  of  each  kind  present.  According  to  Conn,  Bacillus 
lactis  acidi  has  the  highest  relative  growth  at  about  70°  F. 
This  particular  species  produces  no  gas,  and  is  desirable  to  have 
present  in  cream  for  butter-making.  Milk  kept  at  this  tem- 
perature will,  in  most  cases,  providing  it  has  previously  been 
properly  treated,  develop  a  pleasant  acid  taste,  will  curdle  into 
a  smooth  uniform  coagulum,  and  will  contain  a  preponderance 
of  the  species  of  germ  mentioned  above. 

At  as  low  a  temperature  as  50°  F.  acid-producing  types  of 
bacteria  do  not  develop  very  well.  But  Conn  maintains  that 
at  this  temperature  miscellaneous  species  of  bacteria  develop 
that  produce  unfavorable  results.  While  milk  does  not  easily 
sour  at  this  temperature,  it  should  be  remembered  that  un- 
desirable germs  are  constantly  developing. 

As  it  is  practically  impossible  to  exclude  all  of  the  bacteria 
from  milk  during  milking  and  the  handling  of  the  milk,  it 
is  very  essential  that  the  multiplication  of  the  germs  present 
be  checked,  or  at  least  retarded;  and  this  can  be  done  by 
controlling  the  temperature  of  the  milk.  As  low  temperature 
is  effective  in  checking  the  multiplication  of  the  bacteria,  the 
sooner  the  milk  can  be  cooled  after  it  is  drawn,  the  better  it  is 
for  the  keeping  quality  of  the  milk. 

Moisture. — Moisture  is  one  of  the  essentials  for  bacterial 


48  BUTTER-MAKING. 

growth.  As  milk  is  composed  largely  of  water,  bacteria  find  in 
milk  a  good  medium  for  growth.  All  the  other  required  food 
elements  are  also  found  in  abundance  in  milk.  Damp  utensils 
and  rooms  are  always  more  conducive  to  the  growth  of  germs 
than  are  utensils  and  rooms  which  are  thoroughly  dried  and 
ventilated.  This  is  well  illustrated  by  a  refrigerator.  A  very 
damp  dark  refrigerator  is  always  more  conducive  to  the  growth 
of  molds  in  butter  than  is  a  dry  refrigerator. 

Unfavorable  Conditions  for  Bacterial  Growth. — The  reverse 
of  the  favorable  conditions  mentioned  above  would  be  un- 
favorable to  the  growth  of  bacteria.  As  it  is  practically  im- 
possible to  make  conditions  unfavorable  for  the  growth  of 
bacteria  by  taking  away  food,  other  means  must  be  used. 
Extremely  high  temperatures  destroy  bacteria.  Low  tem- 
peratures check  their  growth,  but  so  far  as  known  do  not 
destroy  them.  Absence  of  moisture  and  presence  of  direct 
sunlight  are  conditions  which  are  not  conducive  to  bacterial 
growth.  Certain  chemical  substances  when  added  to  milk,  or 
to  the  medium  in  which  the  bacteria  are  present,  are  very  un- 
favorable to  their  growth.  Some  of  these  chemicals  entirely 
destroy  all  germ  life  when  added  in  even  very  small  quantities. 
These  are  called  disinfectants  (formaldehyde,  corrosive  subli- 
mate, etc.).  Other  chemicals  are  more  mild  in  their  effect  upon 
germ  growth,  and  merely  inhibit  or  retard  the  growth  of  micro- 
organisms. The  chemicals  which  have  this  milder  effect  upon 
germs  are  called  antiseptics.  Boracic  and  salicylic  acids  are 
examples.  Practically  all  disinfectants  are  violent  poisons,  and 
should  not  be  used  in  any  quantity  or  in  any  form  in  milk 
or  dairy  products  which  are  intended  for  human  food.  The 
milder  preservatives,  or  the  antiseptics,  are,  as  a  rule,  not  so 
poisonous  or  injurious  to  human  health.  In  some  countries 
they  are  allowed  to  a  small  extent.  For  instance,  according  to 
reports,  the  laws  of  England  permit  the  use  of  boracic  acid  to 
the  extent  of  0.5  of  one  per  cent.  It  is,  however,  safest  not  to 
use  any  of  these  chemicals,  except  for  preserving  samples  for 
analytical  or  similar  purposes.  As  low  and  high  temperatures 


FERMENTS  IN   MILK.  49 

are  so  effective  in  producing  unfavorable  conditions,  these  should 
be  chiefly  employed  in  controlling  the  growth  of  micro- 
organisms in  the  dairy  industry. 

Kind  of  Germs  Found  in  Milk. — The  number  of  species  of 
germs  found  in  milk  has  not  yet  been  definitely  established, 
due  chiefly  to  the  fact  that  it  is  in  some  instances  difficult 


FIG.  8. — Shows  a  plate  exposed  in  pasture  where  air  must  have  been  very 
pure  and  free  from  germs.     (Bui.  87,  Nebraska.) 

for  bacteriologists  to  differentiate  one  species  from  another. 
The  description  of  one  species  of  bacteria  by  two  different  bac- 
teriologists may  vary  considerably,  as  the  characteristics  of 
the  germs  depend  so  much  upon  the  conditions  throughout 
the  classification  process.  Over  200  different  species  have 
been  described.  It  is  possible,  however,  though  all  of  these 
types  may  have  different  morphological  and  physiological 
characteristics  as  described  by  different  bacteriologists,  that 
some  two  or  more  of  the  200  types  may  belong  to  one  species. 


50  BUTTER-MAKING. 

For  this  purpose,  it  is  sufficient  to  classify  the  bacteria  into 
three  groups;  viz.,  (1)  those  which  are  harmful  to  the  butter- 
making  industry,  (2)  those  which  are  beneficial,  and  (3)  those 
which  are  indifferent,  or  produce  neither  good  nor  bad  results. 

From  the  farmer's  or  milk-producer's  standpoint,  none 
of  these  bacteria  are  desirable.  Each  milk-producer  should 


FIG.  9. — Shows  a  plate  exposed  one-half  minute  under  a  cow's  udder  treated 
with  a  5%  solution  of  carbolic  acid.     (Bui.  87,  Nebraska.) 

make  it  a  point  to  prevent  their  entrance  and  suppress  their 
development  in  milk  and  cream  to  as  great  an  extent  as  pos- 
sible. The  creamery  operator  should  endeavor  to  suppress 
all  of  the  harmful  germs,  and  foster  the  development  of  the 
desirable  ones. 

The  germs  which  are  desirable  belong  chiefly  to  the  acid- 
producing  types.  They  are  often  called  lactic  ferments. 

The  harmful  bacteria  include  those  which  produce  bitter 
milk,  red  milk,  blue  milk,  yellow  milk,  slimy  milk,  etc.  There 


FERMENTS  IN  MILK.  51 

is  a  number  of  species  belonging  to  this  group.  The  patho- 
genic germs,  or  disease-producing  bacteria,  must  also  be  classed 
with  the  harmful  bacteria.  It  is  not  the  intention  in  this 
work  to  give  an  extended  discussion  of  this  subject.  For 
such  discussion  see  special  works  on  Dairy  Bacteriology. 


FIG.  10. — Shows  plate  exposed  one-half  minute  under  cow's  udder  treated 
by  merely  brushing  with  the  hand;  each  little  spot  represents  a  colony 
of  some  kind  of  bacteria.  (Bui.  87,  Nebraska.) 

Number  of  Bacteria  in  Milk. — The  number  of  bacteria 
found  in  milk  varies  so  much  that  it  is  practically  impossible 
to  state  accurately  the  average  number.  The  number  of 
germs  found  varies  according  to  several  conditions,  such  as 
degree  of  cleanliness  of  cows,  utensils,  and  milker;  degree  of 
purity  of  the  atmosphere  when  the  cows  are  milked;  and 
the  temperature  at  which  the  milk  is  kept.  When  the  milk 
is  being  produced  under  the  best  practical  sanitary  conditions, 
the  number  of  germs  need 'not  exceed  10,000  per  c.c.  Such 


52  BUTTER-MAKING. 

results  cannot  be  obtained  unless  extreme  precautions  are 
taken.  Milk  produced  under  average  farm  conditions  sel- 
dom contains  less  than  50,000  germs  per  c.c.  shortly  after  the 
milking.  Milk  which  is  produced  under  filthy  conditions, 
and  which  is  several  hours  old,  may  contain  several  millions 
of  bacteria  per  c.c. 

Sources  of  Bacteria  in  Milk. — Except  in  the  cow's  udder 
where  they  are  present  to  only  a  small  extent,  bacteria  are 
present  almost  everywhere.  They  float  in  the  atmosphere 


FIG.  11. — The  wrong  and  the  right  kind  of  a  milk-pail,  a,  the  ordinary 
type  of  pail  showing  sharp  angle  between  sides  and  bottom;  B,  the  same 
properly  flushed  with  solder  so  as  to  facilitate  thorough  cleaning.  The 
lower  figure  represents  a  joint  as  ordinarily  made  in  tinware.  The  de- 
pression a  affords  a  place  of  refuge  for  bacteria  from  which  they  are 
not  readily  dislodged.  This  open  joint  should  be  filled  completely  with 
solder.  (From  Bui.  62,  Wis.) 

and  adhere  to  particles  of  dust.  Especially  is  this  so  in  the 
dusty  cow-stable.  They  are  present  in  all  well  water  to  a  greater 
or  less  extent.  They  are  very  abundant  in  streams  and  rivers. 
They  are  present  in  the  soil  to  a  depth  of  several  feet,  the 
number  decreasing  with  the  depth.  As  these  germs  are  prac- 
tically present  everywhere,  the  source  of  germs  in  milk  may 
be  said  to  be  all  around  us.  The  principal  sources  of  germs 
in  milk  are,  however,  unclean  dairy  utensils,  unclean  cows, 
and  unclean  surroundings.  As  these  germs  multiply  chiefly 
by  fission,  or  by  one  cell  dividing  into  two,  it  is  plain  that  the 
number  of  germs  will  increase  very  rapidly  under  favorable 
conditions.  Under  the  most  favorable  conditions  it  requires 


FERMENTS  IN  MILK,  53 

approximately  twenty  minutes  for  this  process  of  fission  to 
take  place. 

Some  germs  develop  small  bodies  within  the  cell,  called 
spores.  It  is  not  difficult  to  destroy  the  sporeless  cell  by 
heat,  but  the  spores  are  very  resistant  to  unfavorable  con- 
ditions. The  spore-bearing  bacteria  cannot  be  destroyed  by 
boiling.  The  heating  destroys  the  vegetative  cell,  but  the 
spores  still  remain.  In  order  to  destroy  the  germ  in  the  spore 
form,  it  is  essential  that  the  milk  be  cooled  to  a  temperature 
favorable  to  growth,  and  then  allow  the  spore  to  develop  into 
a  vegetative  cell.  If  heat  is  again  applied,  the  milk  can  be 
rendered  entirely  sterile.  Usually  three  or  four  successive 
heatings  and  coolings  are  necessary  in  order  to  render  the  milk 
completely  sterile.  A  single  heating  under  pressure  (15  minutes 
at  15  pounds)  kills  them  at  once. 

It  has  been  demonstrated  by  several  investigators  that 
freshly  drawn  milk  is  not  a  good  medium  for  bacteria  to  develop 
in.  In  fact,  several  experiments  seem  to  indicate  that  milk 
acts  as  a  germicide  to  certain  varieties  of  bacteria.  For  instance, 
the  cholera  germ  is  to  some  extent  destroyed  in  fresh  milk, 
but  it  is  not  known  to  what  extent.  Organisms  producing 
lactic  acid  check  the  multiplications  of  these  pathogenic  bac- 
teria. This  germicidal  property  is  said  to  be  common,  to  a 
greater  or  less  extent,  to  all  the  animal  secretions. 

Effect  of  Thunder-storms  on  Souring  of  Milk. — It  is  a  common 
impression  that  thunder-storms  hasten  the  souring  of  milk. 
This  was  attributed  to  the  electricity  in  the  air  accompanying 
the  storm.  Experiments  by  several  investigators  have  proved 
that  electricity  does  not  have  any  effect  on  hastening  the  fer- 
mentative changes  of  milk.  The  reason  why  milk  sours  quicker 
when  an  electrical  storm  is  approaching,  is  that  the  air  tem- 
perature is  usually  higher  then  than  at  any  other  time.  This 
higher  temperature  warms  the  milk  and  creates  more  favor- 
able conditions  for  the  rapid  multiplication  of  the  germs  present 
in  the  milk.  It  is  for  this  reason  that  milk  sours  quicker  during 
or  previous  to  a  thunder  storm  than  at  any  other  time. 


CHAPTER  V. 

ABNORMAL  MILK. 

Colostrum  Milk. — Colostrum  is  the  milk  yielded  immediately 
after  calving.  As  the  time  of  calving  approaches,  a  cow  usually 
diminishes  in  her  milk-producing  capacity.  Most  cows  become 
dry  about  two  months  previous  to  parturition.  If  they  do  not 
naturally  stop  giving  milk,  they  should  be  dried  up  so  as  to  have 
a  seven  week's  rest  before  calving.  When  the  rest  has  been 
given,  the  cows  yield,  immediately  after  calving,  milk  which  has 
a  composition  and  characteristics  different  from  those  of  normal 
milk.  If  the  cow  continues  to  give  a  copious  flow  of  milk  up  to 
the  time  of  calving  and  is  not  allowed  any  rest,  the  difference 
in  the  milk  yielded  before  calving  and  after  calving  is  compara- 
tively slight. 

The  composition  of  colostrum  varies  considerably  during  the 
first  three  days  after  calving.  According  to  Engling,  as  reported 
by  Richmond,  the  composition  is  a  follows: 

Water 71.69% 

Fat 3.37 

.,    [Casein 4.83 

Albuminoids -i  ...  1r  0_ 

[  Albumen 15 . 85 

Sugar 2.48 

Ash 1.78 

Colostrum  greatly  changes  in  composition  and  appearance 
as  it  gradually  assumes  the  characteristics  of  normal  milk.  It 
is  at  first  reddish  yellow  in  color,  and  has  a  viscous  and  slimy 

54 


ABNORMAL  MILK.  55 

consistency.  It  is  a  food  which  the  newly  born  calf  should  not 
be  deprived  of,  as  it  seems  to  be  specially  suited  for  the  digestive 
tract  of  the  young  calf. 

It  will  be  seen  from  the  above  table  that  the  water  content 
of  colostrum  is  less  than  that  of  normal  milk.  The  fat  content 
is  a  ittie  lower  than  that  of  normal  milk.  The  most  striking 
characteristics  of  colostrum,  however,  are  the  low  content  of 
sugar,  and  the  large  amount  of  albumen.  Of  the  latter  substance 
very  little  is  present  in  normal  milk.  The  mineral  constituents 
of  colostrum  also  run  quite  high.  The  specific  gravity  of 
colostrum  varies  from  1.046  and  1.079.  When  boiled,  the 
nitrogenous  matter  coagulates.  The  colostrum  is  not  considered 
to  be  suitable  for  food  until  about  four  days  after  parturition. 
Whenever  it  can  be  boiled  without  coagulating,  it  is  claimed 
to  be  safe  to  use.  At  times  a  cow's  udder  becomes  inflamed 
after  calving.  In  such  cases  the  abnormal  qualities  of  the 
cow's  milk  will  extend  over  a  greater  period  of  time  than  that 
mentioned  above. 

Salty  Milk. — The  average  chemical  analysis  of  salty  milk  as 
calculated  from  results  obtained  by  the  analysis  of  such  milk 
from  four  cows  given  by  Boggild,*  is  as  follows: 

Water 91.09 

Fat 2.09 

Nitrogenous  matter 2 . 90 

Sugar 3.01 

Ash 85 

It   has  an  average  specific  gravity  of  1.0244. 

Salty  milk  does  not  occur  very  often,  but  whenever  it  does 
occur,  it  is  difficult,  and,  so  far  as  known,  impossible  to  cure 
without  drying  up  the  cow.  Two  samples  of  such  milk  have 
recently  come  within  the  author's  notice.  It  had  the  appear- 
ance of  normal  milk,  had  a  foul  smell,  and  very  salty  taste. 


*  Maelkeribruget  in  Denmark. 


56  BUTTER-MAKING. 

The  two  samples  contained  1.7%  and  1.9%  of  fat  respectively. 
They  soured  and  curdled  in  a  normal  way  at  living-room  tem- 
perature in  about  thirty  hours.  At  this  stage  they  were  very 
foul  in  smell,  and  unpleasant  in  taste. 

The  cows  which  had  produced  this  milk  had  both  calved 
about  three  months  previously.  It  occurred  in  the  month  of 
July,  when  pastures  were  quite  good.  The  udders  of  the  cows 
were  in  an  apparently  normal  condition.  At  first  it  was  thought 
that  some  conditions  in  the  pasture  caused  this  abnormal  milk. 
The  cows  were  taken  into  the  barn,  and  fed  on  dry  food  for 
two  weeks,  but  without  any  change  in  the  quality  of  the  milk. 
Gradually  they  dried  up. 

The  reason  for  the  secretion  of  this  salty  milk  was  laid  to 
the  long  time  which  the  cows  had  been  yielding  milk  without 
any  rest.  They  had  been  given  no  rest  previous  to  the  last 
calving.  It  is  also  believed  that  this  quality  of  milk  will  occur 
more  frequently  when  the  cows  are  near  the  close  of  their 
lactation  period. 

While  the  above  two  causes  are  perhaps  the  most  common, 
they  are  not  the  only  ones.  Salty  milk  has  been  obtained  from 
cows  to  which  these  reasons  could  not  be  ascribed.  Boggild  has 
found  that  salty  milk  has  been  secreted  by  cows  with  abnormal 
udders.  He  has  also  demonstrated  that  it  was  the  diseased  part 
of  the  udder  from  which  the  salty  milk  was  yielded.  The  healthy 
portion  of  the  udder  yielded  normal  milk.  It  is  possible  that 
an  obscure,  diseased  condition  of  the  udder  may  be  the  entire 
cause. 

Salty  milk  is  of  course  undesirable  in  the  dairy  or  creamery. 
It  is  very  disagreeable  to  the  taste,  and  in  a  fermented  stage 
becomes  very  foul. 

Bloody  or  Red  Milk. — Bloody,  or  red  milk  is  caused,  first, 
by  an  abnormal  condition  of  the  cow's  udder,  which  may  or  may 
not  be  apparent;  and  second,  a  red  color  may  be  developed  in 
milk  after  standing,  through  the  action  of  bacteria. 

The  bloody  milk,  caused  by  an  inflamed  udder,  often  assumes 
a  reddish-yellow  appearance,  and  may,  if  not  examined  care- 


ABNORMAL  MILK.  57 

fully,  be  mistaken  for  colostrum.  Bloody  milk  produced  by  an 
inflamed  udder,  may  be  distinguished  by  noticing  small  blood 
particles,  which  will  settle  to  the  bottom,  and  can  be  noticed  if 
the  sample  is  placed  in  a  glass  test-tube.  Bloody  milk  caused  by 
bacterial  growth  does  not  show  the  blood  at  the  bottom,  but 
instead,  previous  to  stirring  the  milk  or  cream,  it  appears  on 
the  surface  in  small  red  dots.  The  red  color  which  commonly 
occurs  in  milk  is  due  chiefly  to  a  species  of  germ  called  Micro- 
coccus  prodigiosus.  Colostrum  will  show  reddish  cream  on  the 
surface,  but  no  blood-like  material  will  separate  out. 

Blue  Milk. — Blue  milk  is  quite  commonly  found.  Formerly 
it  was  thought  that  this  color  was  due  to  the  condition  of  the 
casein  in  the  milk,  but  since  more  has  been  discovered  in  regard 
to  the  effect  of  germ  life  upon  conditions  and  properties  of  milk, 
it  has  been  proved  that  blue  milk  is  caused  by  bacteria*  (Bacil- 
lus cyanogenus).  This  particular  germ  produces  the  blue  color 
in  the  milk  only  when  the  milk  has  an  acid  reaction.  When 
sterile  milk  is  inoculated  with  this  particular  germ,  the  blue 
color  is  not  produced,  but  by  the  addition  of  a  little  acid,  or  by 
inoculating  the  milk  with  the  bacteria  that  produce  lactic  acid, 
the  blue  color  is  produced.  This  seems  to  be  one  of  the  instances 
of  symbiotic  action  of  bacteria  in  milk.  There  are  probably 
other  causes,  but  they  are  not  known.  This  germ,  according 
to  Aikman,  is  killed  by  heating  the  milk  to  about  176°  F.  The 
germ  ceases  to  work  as  soon  as  milk  is  coagulated. 

Yellow  Milk. — According  to  Aikman,*  yellow  milk  is  caused 
chiefly  by  one  species  of  bacteria,  named  Bacillus  synxanthus. 
This  micro-organism  belongs  to  the  group  of  ferments  that  act 
upon  the  fat  of  milk.  There  are  different  shades  of  yellow 
produced  in  milk,  caused  by  different  species  of  bacteria,  but 
the  above-mentioned  one  is  considered  to  be  the  principal  cause. 
Some  produce  a  brilliant  yellow  color,  while  other  species  first 
curdle  the  casein,  and  then  digest  or  dissolve  it  into  a  yellow 
or  amber-colored  liquid. 

*  C.  M.  Aikman,  in  "Milk,  Its  Nature  and  Composition." 


BUTTER-MAKING. 


Ropy  Milk. — The  slimy  or  ropy  condition  of  milk  is  not 
common.  It  is  sometimes  found  in  milk  handled  by  milk- 
dealers  and  is  caused  by  certain  micro- 
organisms. Aikman  mentions  the  fact  that 
no  less  than  eighteen  different  distinct  organ- 
isms have  been  identified  as  associated  with 
this  slimy  fermentation.  Most  of  the  inves- 
tigators agree  that  two  organisms  are  chiefly 
responsible  for  this  slimy  condition.  One  of 
these  is  Bacillus  lactis  viscosus.*  This  germ 
has  been  found  to  be  frequently  present  in 
surface  wraters.  The  very  fact  that  milk- 
dealers  in  cities  are  occasionally  troubled  with 
this  sliminess  in  milk  indicates  that  precau- 
tions are  essential  in  order  to  avoid  the  pres- 
ence of  this  ferment  in  milk.  This  germ,  when 
it  once  gains  entrance  to  a  milk  establishment, 
is  very  difficult  to  eradicate.  In  order  to 
overcome  this  trouble  it  may  be  necessary 
to  cover  the  whole  inside  of  the  milk-store, 
and  all  of  the  vessels  used  for  handling  the 
milk,  with  sour  coagulated  milk.  The  lactic 
acid  germs  present  in  this  milk  gains  ascend- 
FlG-i,  l  2-,~rslir^7  ency  over  the  germs  causing  sliminess,  and 

milk;      this    milk  .       * 

would    "string  in  that  way  the  trouble  may  be  eradicated. 


Streptococcus  hollandicus  f  is  another  spe- 


ouf'in  fine  threads 
several      feet      in 

length.  (From  Bui.  cies  which  produces  sliminess  in  milk.    This 

62,  Wis.)  .  . 

particular  organism  is  used  in  Holland  as  a 
starter.  The  starter  containing  this  particular  germ  is  added 
to  the  milk  used  in  the  manufacture  of  Edam  cheese,  in  order 
to  control  or  check  the  gassy  fermentation  which  may  be  present 
in  it. 

Bitter  Milk. — This  is  one  of  the  most  common  kinds  of 
abnormal  milk,  and  like  some  of  the  others,  may  have  more 

*  Adametz  Landw.  Jhr.,  1891,  p.  185. 
f  Milch  Zeit.,  1889,  p.  982. 


o 

•s 

co 

12 
3 


c  A 

o  i 

'^3  o3 

03  60 


6 


60  BUTTER-MAKING. 

than  one  cause.  It  may  be  due  to  some  undesirable  food  that 
the  cow  has  eaten,  or  to  the  development  of  certain  germs  in 
the  milk.  If  caused  by  the  food  eaten  by  the  cow,  the  bitter 
taste  is  recognizable  immediately  after  the  milk  has  been  drawn. 
If  it  develops  on  letting  the  milk  stand,  it  is  caused  by  bac- 
terial growth. 

Several  germs  have  been  found  to  be  associated  with  the 
production  of  this  bitter  flavor  in  milk.  Conn  has  described  a 
micrococcus  which  produces  a  bitter  flavor  in  milk.  Weig- 
mann  has  described  a  bacillus  which  also  produces  bitter 
flavors.  Nearly  all  of  the  investigators  agree  that  the  germs 
causing  the  bitter  flavors  in  milk  belong  to  the  group  which  acts 
upon  the  casein  in  milk.  The  bitter  flavor  is  most  commonly 
found  in  milk  that  has  been  heated,  and  then  cooled  to  a  low 
temperature.  The  heat  destroys  the  bacteria  that  produce 
lactic  acid,  but  does  not  kill  those  that  produce  the  bitter 
flavor,  owing  to  the  fact  that  they  are  spore-producing. 

The  germs  that  produce  a  bitter  flavor  do  not  develop  in 
milk  that  is  partly  soured,  because  an  acid  reaction  is  un- 
favorable to  their  growth. 

It  was  formerly  thought  that  the  organisms  that  cause  the 
bitter  flavor  in  milk  produced  butyric  acid.  This  theory, 
however,  has  been  largely  overthrown,  as  it  has  been  found  that 
the  germs  causing  bitter  flavor  are  chiefly  of  the  kind  which 
peptonize  the  casein  and  produce  gas. 

Milk  from  Cows  which  have  Been  in  Milk  for  a  Long  Period. 
— The  difference  in  the  composition  of  the  fat  yielded  by  cows 
in  different  stages  of  the  lactation  period  seemingly  does  not 
affect  the  quality  of  the  milk  to  a  noticeable  extent.  If  the 
cows  have  been  giving  milk  an  unusually  long  time,  then  the 
milk  may  become  abnormal. 

The  impurities  in  the  small  amount  of  milk  yielded  by  cows 
almost  dried  up  are  quite  apparent,  and  the  causes  of  the 
presence  of  these  impurities  are  readily  understood.  The 
small  amount  of  milk  drawn  from  such  a  cow  would  contain 
a  proportionately  larger  amount  of  dirt  and  germs  than  would 


ABNORMAL  MILK.  61 

a  larger  amount  of  milk  drawn  from  a  cow  yielding  more  milk, 
providing  the  cleanliness  of  the  udder  and  manner  of  milking 
were  the  same.  Cows  giving  a  good  quantity  of  milk  always 
seem  to  have  a  cleaner  udder.  This  has  been  laid  to  the  more 
vigorous  circulation  of  the  blood  in  the  udder  of  the  cow  that 
yields  a  larger  portion  of  milk. 

AVhen  cows  calve  once  a  year,  and  have  rest  of  about  seven 
weeks  previous  to  parturition,  if  proper  precautions  are  taken 
concerning  cleanliness,  they  seldom  yield  milk  from  which  a 
first-class  quality  of  butter  cannot  be  produced.  In  practice 
this  regularity  of  calving  does  not  always  exist.  Several  in- 
stances have  come  within  the  author's  notice  where  cows  have 
been  in  milk  for  t\vo  years  or  more  without  coming  in  fresh. 
Such  a  condition  happens  quite  frequently  on  small  farms, 
where  the  cows  kept  are  so  few  that  it  is  deemed  imprac- 
ticable to  keep  a  bull.  As  a  consequence  cows  are  not 
served  at  the  proper  time,  and  great  irregularities  in  calving 
are  introduced. 

At  times  it  also  happens  that  cows  become  barren.  In 
such  a  case  they  are  usually  milked  as  long  as  they  will  pro- 
duce even  a  very  small  quantity  of  milk.  Milk  produced  under 
such  conditions  is  likely  to  become  abnormal  in  character. 
It  may  remain  normal  with  a  slight  increase  in  the  fat-content. 
The  abnormal  milk,  so  often  complained  of,  is  usually  brought 
about  by  similar  circumstances.  It  is  a  common  belief  that 
milk  yielded  from  such  animals  always  contains  a  high  fat- 
content,  but  it  may  contain  very  little  fat.  It  may  be  salty. 
It  may  also  appear  normal,  and  the  cream  when  separated 
appear  viscous  and  dead.  Boggild  states  that  the  milk  at  the 
creamery  from  one  barren  cow  has  more  than  once  pro- 
duced difficult  churning. 

Milk  from  Spayed  Cows. — H.  Lennat  has  given  this  kind  of 
milk  considerable  study.  He  finds  that  milk  from  spayed 
cows  may  vary  in  quality  to  the  same  extent  as  milk  from  normal 
cows.  The  solids  of  milk,  as  a  rule,  increase  as  the  spayed 
cow  advances  in  the  milk-giving  period.  Especially  was  this 


62  BUTTER-MAKING. 

noticeable  in  the  fat,  sugar,  and  casein.  Such  milk  is  con- 
sidered to  be  of  extra  good  quality,  and  is  recommended  as 
being  especially  suitable  for  infant-feeding. 

Milk  from  Sick  Cows. — Too  much  cannot  be  said  against 
the  use  of  milk  from  sick  cows.  As  soon  as  the  cows  decline 
in  health,  the  quantity  will  be  noticeably  decreased,  and  the 
quality  is  usually  abnormal.  The  kind  of  milk  yielded  varies 
with  different  cows  and  different  diseases,  but  it  is  interesting 
to  note  from  the  study  of  this  subject,  by  several  men,  that 
the  milk-secreting  glands  are  quickly  affected  by  disease  and 
are  unable  to  perform  their  proper  functions.  Even  a  slight 
derangement  of  the  digestive  organs  is  said  to  have  a  marked 
influence  upon  the  flavor  of  the  milk  and  butter.  When  cows 
do  not  clean  well  after  calving,  the  milk  secreted  by  them 
always  has  an  undesirable  taste.  During  the  time  of  sexual 
excitement  of  the  cow,  milk  is  usually  decreased  in  quantity, 
and  in  a  great  many  instances  assumes  a  very  disagreeable  flavor. 

When  a  cow's  udder  is  inflamed,  the  milk  usually  assumes 
an  abnormal  condition.  It  usually  contains  large,  white, 
slimy  lumps.  According  to  Bang,*  this  is  caused  by  a  small 
round  bacterium,  and  is  contagious.  When  this  germ  is  in- 
oculated into  the  udder,  the  cow  gets  feverish  and  the  milk 
becomes  slimy. 

When  cows  become  infected  with  tuberculosis  to  such  an 
extent  that  the  udder  shows  lesions  and  nodules,  then  the 
composition  and  appearance  of  the  milk  is  altered  consider- 
ably. Milk  from  such  cows  contains  tubercle  germs,  appears 
yellowish  brown  in  color,  and  has  an  alkaline  reaction.  The 
composition  of  such  milk  has  been  studied  in  Denmark  and 
reported  by  Boggild  to  be  as  follows: 

Water 88.79 

Fat 3.55 

Albuminoids 5 . 69 

Sugar 1.25 

Ash 94 

*  Maelkeribruget  i  Danmark,  by  Boggild. 


ABNORMAL  MILK. 


FIG.  14. — The  carcass  of  an  animal  killed  for  beef,  showing  tuberculosis  of 
the  liver,  omentum,  and  lungs.  Generalized  tuberculosis.  (Bui.  229, 
Cornell,  N.  Y.) 


64  BUTTER  MAKING. 

These  results  represent  the  average  of  four  samples  taken 
from  the  diseased  part  of  the  udder.  It  will  be  seen  that  the 
greatest  variation  from  normal  milk  exists  in  the  small  amount 
of  sugar  it  contains  and  the  high  per  cent  of  ash  and  nitrog- 
enous matter. 


CHAPTER  VI. 

VARIATION   OF   FAT  IN  MILK. 

THE  percentage  of  fat  in  normal  milk  varies  a  great  deal 
more  than  any  other  of  the  constituents  of  milk.  Dr.  Rich- 
mond reports  that  the  fat  of  milk  may  go  as  low  as  1.04%  and 
as  high  as  12.52%.  Such  extreme  variations  are,  of  course, 
abnormal.  The  fat-content  seldom  falls  below  2|%  or  rises 
above  7%.  The  fat-content  of  milk  from  a  whole  herd  of 
cows,  varies  only  within  comparatively  narrow  limits.  The 
following  are  the  chief  factors  which  cause  the  fat-content 
of  milk  to  vary: 

(1)  Individuality  of  cows. 

(2)  Breed  of  cows. 

(3)  Time  between  milkings. 

(4)  Manner  of  milking. 

(5)  Whether  the  milk  is  fore  or  after  milk. 

(6)  Age  of  cow. 

(7)  Lactation  period. 

(8)  Feed  of  cows. 

(9)  Environmental  conditions. 

i.  Individuality  of  Cows. — That  the  quantity  of  milk  from 
individual  cows  varies  is  a  fact  that  is  well  known  to  every- 
one who  keeps  cows,  but  the  average  cow-keeper  does  not  very 
well  apprehend  that  the  percentage  of  fat  is  as  variable  a  factor 
as  it  really  is.  As  a  rule,  when  a  cow  yields  only  a  small  quantity 
of  milk  she  is  in  many  instances  condemned  without  taking 
the  quality  into  consideration.  If  the  fat  content  were  taken 

65 


66  BUTTER-MAKING. 

into  consideration,  such  a  cow  might  prove  more  profitable 
to  keep  than  another  that  yields  a  larger  quantity  of  milk. 
For  this  reason  the  yield  of  fat  is  a  better  standard  by  which 
to  judge  the  value  of  a  cow  than  the  quantity  of  milk.  Since 
the  general  introduction  of  the  Babcock  test  for  the  deter- 
mination of  fat  in  milk,  the  fat-content  of  milk  can  be  easily 
determined,  even  on  the  farm.  The  importance  of  testing 
the  milk  of  each  cow  in  a  herd  is  sufficient  to  warrant  every 
cow  owner  to  have  a  complete  Babcock  testing  outfit  on  the 
farm. 

Unprofitable  cows  are,  and  have  been,  a  serious  draw- 
back to  dairy  progress.  According  to  Dairy  Commissioner 
Wright's  reports,  the  average  yield  of  butter  per  cow,  in  the 
State  of  Iowa,  is  less  than  140  pounds  per  year.  Some  of  the 
cows  from  which  these  statistics  were  calculated  evidently 
gave  good  returns  to  the  owners,  while  others  again  would 
run  their  owners  in  debt.  Cases  are  on  record  where  single 
cows  have  produced  more  than  eight  hundred  pounds  of  butter 
annually.  Such  a  yield  is  the  result  of  a  great  many  years 
of  attention  to  the  selection  and  breeding,  and  can  be  obtained 
only  in  special  cases.  A  yield  of  400  pounds  of  fat  per  cow 
annually  might  be  a  good  standard  for  which  to. strive.  Even 
if  the  average  annual  butter  yield  per  cow  could  be  brought 
up  to  300  pounds,  the  dairy  industry  would  be  put  on  a  sounder 
and  more  profitable  basis.  The  average  price  of  butter  is 
about  twenty  cents  per  pound.  At  this  rate  300  pounds  of 
butter  would  be  worth  $60.00.  The  average  cost  of  keeping  a 
cow  in  the  State  of  Iowa  is  about  $35.00,  including  care  and 
feed.  This  would  leave  a  net  profit  of  $25.00  per  cow.  If 
a  cow  yielded  only  140  pounds  per  year,  which  at  20  cents 
would  be  worth  $28.00,  the  owner  of  that  cow  would  suffer 
a  loss  of  $7.00.  It  must  not  be  forgotten  that  the  above  cal- 
culation is  based  only  upon  the  butter-fat.  The  calf  and  the 
skimmed  milk  are  not  taken  into  consideration.  The  skimmed 
milk  is  worth  25  cents  per  hundred  pounds  for  feeding  pur- 
poses, and  the  calf  is  worth  about  $3.00. 


GUERNSEY  Cow  (OUSTER'S  BELLE,  9514). 

Owned  and  bred  by  W.  D.  Hoard,  Fort  Atkinson,  Wis.  Calved  when 
two  years  old.  She  produced  that  year  42!)  pounds  of  butter-fat.  Periodical 
weighing  of  milk  every  seventh  week  and  testing  showed  that  she  had  pro- 
duced OP)49  pounds  of  milk  containing  314  pounds  of  fat  in  eight  months 
ending  Sept.  14,  1905.  She  calved  again  Jan.  15,  1905.  The  above  records 
we  e  made  under  ordinary  feeding  and  management  such  as  the  whole  herd 
received. 


VARIATION  OF  FAT  IN  MILK.  67 

TABLE  BY  GURLER,  SHOWING  RECORDS  OF  INDIVIDUAL  Cows. 


"3 

*& 

c3  «' 

4 

«4 

-4 

.-3 

QJ 

+  1 

|g 

iM 

"S 

-1 

Bj3 

2s 

"Sfe 

£  a 
3-g 

"5  S 

sj 

"S-g 

II  II 

-*^   00 

tC  <» 

Is 

Sia 

i<  'S 

-+-  O 

£>ffl 

?flQ 

Soj 

"o  c 

C[S 

00 

& 

* 

(g» 

H 

>w 

_ 

> 

H" 

0 

PH 

Av.  of 

50  cows 

5708 

4.47 

255.2 

297.7 

59.54 

5453 

14.00 

73.57 

41.06 

+  19.98 

244 

2382.5 

4.87 

116.13 

135.48 

27.09 

2266 

5.66 

32.75 

31.23 

-11.00 

154 

3619 

4.51 

163.4 

190.63 

38.12 

3494 

8.64 

46.76 

41.06 

-   6.80 

44 

3399 

4.58 

155.94 

181.93 

36.86 

3243 

8.10 

44.48 

37.32 

-  5-34 

72 

2661 

5.06 

134.97 

157.46 

31.49 

2526 

6.31 

37.80 

26.45 

-    1.15 

308 

4617 

3.83 

177.16 

206.68 

41.43 

4440 

11.03 

52.36 

39.32 

+   0.44 

184 

7997 

4.77 

382.04 

445.71 

89.14 

7615 

19.14 

108  .  28 

44.32 

+  51.46 

262 

9297 

5.03 

372.56 

434.65 

86.93 

8900 

22.00 

109.02 

44.72 

+  51.80 

283 

10151 

3.68 

374.76 

436.75 

87.35 

9777 

24.44 

111.79 

44.72 

+  54.57 

129 

8449 

4.52 

406.73 

472.18 

94.43 

8545 

21.36 

115.80 

46.06 

+  57.24 

Av.  of  4 

best 

9098 

4.25 

384.00 

447.32 

89.46 

8709 

21.76 

111.22 

44.95 

+  53.77 

Av.  of  4 

poorest 

3020 

4.75 

142.60 

160.40 

33.28 

2881 

7.20 

40.48 

33.96 

-   5.98 

Av.  of  9 

cows 

5897 

4.43 

253.5 

295.7 

59.14 

5644 

14.11 

73.25 

39.46 

+  21.25 

In  making  the  calculations  in  the  above  table  the  price  of 
butter  per  pound  was  taken  as  20  cents,  the  skimmed  milk 
was  considered  to  be  worth  25  cents  per  hundred  pounds,  and 
the  cost  of  labor  was  taken  at  $12.50  per  cow. 

Breed  of  Cows. — There  is  a  marked  difference  in  the  milk 
secreted  by  different  breeds  of  cows.  The  most  striking  differ- 
ence is,  perhaps,  between  the  Holstein  and  the  Jersey  breeds. 
The  former,  as  a  rule,  yields  a  large  quantity  of  milk,  with  a 
comparatively  low  fat-content;  the  latter,  as  a  rule,  yields 
a  comparatively  small  quantity  of  milk,  with  a  high  per- 
centage of  fat.  The  influence  of  individuality  of 'cows  must 
not  be  overlooked  in  this  connection. 

It  is  said  that  the  color  of  the  skin,  and  of  the  fine  hairs  on 
the  exterior  of  the  cow's  udder  may  be  taken  as  a  guide  in 
selecting  cows  for  breeding  purposes.  A  fine  soft  skin,  darkish 
golden  yellow  in  color,  enveloping  the  milk -glands,  and  covered 
with  fine  soft  hair,  are  considered  indications  of  rich  milk. 
While  the  Jersey  cows  perhaps  yield  milk  with  a  higher  fat- 


68 


BUTTER-MAKING. 


content  than  any  other  breed,  a  high  percentage  of  fat  is  char- 
acteristic of  the  milk  from  all  the  Channel  Island  breeds.  On 
account  of  the  great  variation  in  the  composition  of  milk  from 
different  cows,  it  is  difficult  to  get  results  from  experiments 
where  the  number  of  cows  involved  in  each  breed  and  trial 
have  been  so  numerous  as  to  overcome  the  individuality  of 
the  cow.  We  quote  the  following  table,  which  shows  the 
average  results  from  the  breed  tests  conducted  at  the  Annual 
Dairy  Shows  of  the  British  Dairy  Fanners'  Association  between 
the  years  1879  and  1893,  inclusive: 


Total 
No.  of 
An  i- 
mals. 

Breed. 

Average 
Milk 
Yield. 
Lbs. 
Daily. 

Total  Solids. 

Fat. 

Solids, 
Not 
Fat, 
Per 
Cent. 

Live 
Weight. 

Per 
Day, 
Lbs. 

Per 
Cent. 

Per 
Day, 
Lbs. 

Per 

Cent. 

147 
U9 
63 
10 
18 
2 
8 
1 
1 
12 

30 

Shorthorn     .... 

43.86 
27.36 
28.95 
45.19 
37.82 
30.12 
35.10 
46.00 
60.30 

26.59 
42.05 

5.64 
3.98 
4.07 
5.53 
5.09 
4.32 
4.55 
5.86 
8.29 

3.56 
5.41 

12.86 
14.54 
14.05 
12.25 
13.45 
14.34 
12.96 
12.74 
13.74 

13.37 

12.87 

1.65 
1.33 
1.38 
1.54 
1.60 
1.48 
1.38 
1.91 
3.01 

1.11 
1.56 

3.77 
4.85 
4.78 
3.41 
4.22 
4.90 
3.92 
4.16 
4.99 

4.18 
3.70 

9.09 
9.69 

9.28 
8.84 
9.23 
9.44 
9.04 
8.58 
8.75 

9.19 
9.17 

1403 
832 
1033 
1383 
1060 

1201 

749 
1362 

Jersey   

Guernsey          .  . 

Holstein   

Ayrshire  

Devons.  •  

Red  Polls     .  .  . 

Welsh 

Aberdeen-  Ang  .  . 
Kerries          and 
Dexters      .... 

Crosses      

These  results  agree  very  closely  with  tests  carried  on  in 
the  United  States,  with  the  exception  of  the  two  breeds,  Welsh 
and  Aberdeen  Angus.  The  former  breed  is  rare  in  this  country. 
The  latter  breed  is  considered  to  be  quite  inferior  as  a  milk- 
producing  breed,  but  one  of  the  best  beef  types  known.  The 
results  obtained  in  the  test  above,  where  only  one  cow  was 
involved,  are  abnormal  and  cannot  represent  the  average  of 
Angus  cows'  milk. 

Time  Between  Milkings. —  The  common  practice  in  the 
United  States  is  to  milk  twice  during  twenty-four  hours,  every 
morning  and  evening.  The  intervals  between  these  milkings 
are  not  always  of  the  same  length.  Under  the  average  farm 


JERSEY  Cow  (LORETTA  I),  141,708,  A.  J.  C.  C.). 

Owned  by  W.  S.  Ladd,  Portland,  Oregon.  Record  at  St.  Louis  Expo- 
sition from  June  16  to  Oct.  13,  19  H,  (120  days.)  5802.7  pounds  of  milk  con- 
taining 280.16  pounds  of  fat.  Vahie  of  feed  consumed  $31  99  Dropped 
Oct.  13,  1893.  Weight  1075  ponnds 


FIG.  16. — First  manipulation  of  udder,  right     FIG.  17. — First  manipulation,  left  quarters, 
quarters. 


FIG.  18. — Second  manipulation,  right  fore-quarter. 


FIG.  19. — Second  manipulation,  right  hind-  FIG.  20. — Third  manipulation, 

quarter,  rear  view. 

[ILLUSTRATING  HEGELUND  METHOD  OF  MILKING.     (From  Report  of  Kansas  State  Board 
of  Agriculture,  No.  87,  1903.) 

71 


71o 


BUTTER-MAKING. 


Milking-machines.* — For  a  long  time  successful  milking- 
machines  have  been  expected  by  dairy  enthusiasts.  Seem- 
ingly these  expectations  have  been  fulfilled.  Many  large 
dairy  farmers  are  now  operating  such  machines.  The  Bur- 
rell  -  Lawrence  -  Kenedy  milking-machine  and  the  Globe  are 
two  of  the  machines  which  under  proper  conditions  and 


FIG.  20a. — The  Globe  milking-machine. 

care  have  been  found  to  operate  successfully  in  the  United 
States. 

The  cost  of  installation,  and  care  and  skill  necessary  in 
jconomic  operations,  are  factors  which  retard  their  use  on  the 


*  Bulletin  No.  92,  Bureau  of  Animal  Industry,  U.  3.  Dept.  of  Agr. 
Bulletin  No.  47,  Storr's  Experiment  Station,  Conn. 
Bulletin  No.  140,  Manhattan,  Kans. 


VARIATION   OF  FAT   IN  MILK. 


716 


FIG.  206. — The  Burrell-Lawrence-Kenedy  milking-machine. 


FIG.  20c. — A  foot-power  cow-milker  with  attachments.     (Mehring.) 


72 


BUTTER-MAKING. 


average  sized  dairy  farms.  If  a  man  keeps  at  least  twenty 
good  cows  in  milk  at  the  time,  and  makes  dairying  a  business, 
not  a  side  issue,  and  is  willing  and  able  to  care  for  the  machine 
as  it  should  be  cared  for,  then  the  milking-machine  can  appar- 
ently be  economically  and  successfully  operated.  The  milking- 
machine  question  is  still  in  a  transitional  period  and  shall  not 
be  considered  in  detail  at  this  writing. 


FIG.  21. — De  Schmidt  milking-machine. 


All  of  the  above  machines  are  represented  by  their 
respective  inventors  and  manufacturers  to  do  successful 
work.  Whether  a  milking-machine  will  ever  be  perfected 
which  can  imitate  nature's  methods  as  closely  as  the  human 
hands,  is  a  question  which  has  yet  to  be  solved. 


AN  UNREGISTERED  BUT  PURE-BRED  AYRSHIRE  Cow. 
Owned  by  C.  C.  Burr,  St.  Charles,  111.     In  the  year  1902-3,  under  ordinary 
farm  conditions  and  feeding,  she  gave  8467  pounds  of  milk  which  contained 
342  pounds  of  butter-fat. 


VARIATION  OF  FAT  IN  MILK  73 

According  to  experimental  evidence,  milk  drawn  with  a 
machine  contains  more  bacteria  than  milk  drawn  by  hand. 
This  is  claimed  to  be  due  to  the  suction  on  the  exterior  of  the 
teat,  and  to  the  tubes  through  which  the  milk  must  pass  after 
it  is  drawn. 

Fore-milk  and  After-milk.  —  The  fore-milk,  or  the  milk 
drawn  from  the  cow's  udder  first,  contains  much  less  fat  than 
does  the  milk  drawn  subsequently.  The  very  first  milk  drawn 


FIG.  22. — Milking  goats  in  Norway. 

appears  watery  and  contains  as  little  as  0.1%  of  fat,  while 
the  very  last  milk  in  the  udder  may  contain  as  high  as  12%. 

The  reasons  assigned  for  this  variation  are  (1)  the  milk  in 
the  canal  of  the  teat,  and  lower  portion  of  the  milk-reservoir 
is  present  under  such  conditions  as  to  allow  creaming  to  proceed. 
(2)  The  larger  fat-globules  are  about  as  large  as  the  smaller 
milk-dusts  in  the  cow's  udder;  consequently  the  downward 
passage  of  these  fat-globules  meets  with  some  obstruction 


74  BUTTER-MAKING. 

and  they  are  drawn  out  only  when  the  last  milk  is  removed. 
(3)  The  fore-milk  has  been  subjected  to  a  re-absorption  process 
of  the  lymphatics.  The  third  factor  perhaps  plays  only  a 
small  part  in  reducing  the  fat-content  of  the  fore-milk.  As 
the  fore-milk  contains  so  very  little  fat,  and  a  great  many 
micro-organisms,  it  is  often  advantageous  to  reject  the  first 
few  streams  of  milk.  Especially  is  this  important  when  sani- 
tary milk  is  desired. 

It  is  in  many  instances  customary,  in  order  to  apportion 
the  calf  a  certain  amount  of  milk,  to  first  partly  milk  the  cow 
by  hand,  and  send  this  milk  to  the  creamery,  and  then  allow 
the  calf  to  suck  the  remainder.  The  results  of  such  procedure 
are  plain,  yet  it  is  practiced  to  a  large  extent.  When  dis- 
covered, it  has  in  many  instances  explained  why  a  certain 
creamery  patron's  milk  has  been  testing  low  at  the  creamery. 

Age  of  Cow. — There  is  a  time  during  the  life  of  a  cow  when 
she  is  most  vigorous  and  most  productive.  At  the  time  she 
first  calves  (about  three  years  old)  the  cow  or  heifer  is  still 
growing,  and  her  milk-producing  capacity  is  not  so  great  then 
as  it  is  later  on,  when  she  becomes  matured.  After  this  increase 
in  quantity  there  is  also  a  slight  increase  in  quality.  At  the 
age  of  about  seven  years  the  cow  is  usually  at  her  best.  As 
the  cow  advances  in  age,  usually  the  quantity  and  quality 
diminish.  However,  the  individuality  of  cows  prevents  draw- 
ing any  definite  line.  In  some  cows  age  has  considerable 
effect,  while  in  others  age  has  but  little  effect. 

Lactation  Period. — By  lactation  period  we  understand  the 
milking  period,  from  the  time  of  calving  until  the  cow  is  dried 
up.  The  first  few  days  after  calving,  the  cow  yields  milk 
which  is  rich  in  solids,  not  fat.  The  fat-content  in  milk  from 
most  cows  usually  increases  a  trifle  during  the  first  two  weeks 
after  parturition.  Then,  when  conditions  are  normal  and  uni- 
form, the  percentage  of  fat  is  nearly  constant  for  about  three 
months.  After  this  time  the  quantity  decreases  and  the 
quality  gradually  increases  a  trifle.  This  applies  more  fully 
if  the  cow  is  pregnant.  Most  cows  calve  in  the  spring  of  the 


SHORT-HORN  Cow  (COLLEGE  MOORE). 

Owned  by  Iowa  State  College,  Ames,  la.  She  produced  9896.5  pounds 
of  milk  containing  406.8  pounds  of  fat  during  one  milking  period  extend- 
ing over  393  days  beginning  Oct.  4,  1899.  Weight  1695.8  pounds. 


VARIATION  OF  FAT  L\  MILK.  75 

year,  and  as  a  consequence  milk  usually  tests  a  little  higher  in 
the  fall. 

Food  of  Cows. — For  a  long  time  it  was  thought  that  the 
kind  of  food  had  considerable  influence  upon  the  fat-content  of 
milk,  but  later  experiments  in  this  country,  as  well  as  in  foreign 
countries,  have  almost  completely  demonstrated  that  food  has 
practically  no  effect  upon  the  quality  of  milk.  Investigators 
agree  that  foods  may  affect  the  fat  content  of  milk  by  increasing 
the  quantity  of  milk,  without  reducing  the  per  cent  of  fat,  thus 
increasing  the  total  amount  of  fat.  Extensive  experiments 
were  carried  on  in  Denmark,  where  more  than  one  hundred 
and  fifty  cows  were  involved  in  each  experiment,  on  ten  different 
estates,  in  order  to  determine  the  effect  of  food  upon  the  per- 
centage of  fat  in  the  milk.  Roots  of  different  kinds,  which 
are  very  succulent,  were  fed  with  out  reducing  the  per  cent 
of  fat.  Different  concentrated  feeds  (oil -cake,  wheat,  bran, 
ground  barley,  and  oats)  were  also  fed  with  a  view  of  increasing 
the  percentage  of  fat,  but  without  any  noticeable  effect.  The 
New  York  Station  found,  through  carefully  conducted  experi- 
ments, that  feeding  tallow  to  cows  did  not  increase  the  percent- 
age of  fat  in  the  milk. 

Soxhlet  found  that  by  feeding  tallow,  in  the  form  of  an 
emulsion,  for  a  considerable  time,  he  was  able  to  increase  the 
percentage  of  fat  in  the  milk.  The  Iowa  Experiment  Station 
also  reported  that  the  percentage  of  fat  could  be  increased  by 
feeding  oil  meal.  Dr.  Lindsey,  at  the  Hatch  Experiment 
Station,  Massachusetts,  recently  found  that  fat  can  be  slightly 
increased  by  the  use  of  certain  foods  rich  in  oil. 

But  on  the  whole,  the  results  reached  so  far  show  that 
different  foods  have  little  influence  on  the  percentage  of  fat  in 
the  milk.  Especially  is  this  so  under  practical  condi- 
tions. 

On  the  other  hand,  different  kinds  of  foods  affect  the  compo- 
sition of  the  fat  itself.  Gluten  meal,  in  fact  all  gluten  products, 
produce  butter  containing  a  high  per  cent  of  olein,  and  usually 
an  increase  in  the  volatile  fats.  Cottonseed-oil  produces  a 


76  BUTTER-MAKING. 

decrease  in  the  volatile  fats,  and  makes  butter  noticeably 
harder  and  more  tallowy  in  appearance. 

Environment. — Unfavorable  environmental  conditions  im- 
posed upon  a  cow,  such  as  sudden  changes  in  temperature, 
storms,  impure  surroundings,  and  ill-ventilated  barns,  are 
certain  to  decrease  the  flow  of  milk ;  and  if  they  are  continued  a 
few  days,  the  percentage  of  fat  in  the  milk  will  decrease  also.  In 
a  general  way  it  might  be  said  that  any  unfavorable  condition 
which  causes  a  decrease  in  the  quantity  of  milk  will  cause  a 
slight  increase  in  the  percentage  of  fat  during  the  first  few  days. 
But  if  the  cow  is  surrounded  with  these  unfavorable  conditions 
for  any  length  of  time,  the  percentage  of  fat  will  again  decrease. 
It  is  possible,  however,  by  ill  treatment,  to  diminish  the  fat- 
content  greatly. 

Exercise,  also,  affects  the  yield  of  milk,  as  well  as  the  quality. 
Uninterrupted,  long  confinement  in  a  stall  is  detrimental  to 
a  cow's  health.  For  a  time  it  shows  no  effect  upon  the  quan- 
tity and  quality  of  the  milk,  but  eventually  it  will  decrease 
both.  However,  many  Danish  dairy  farmers  keep  their  cows 
in  the  barn  all  winter,  without  letting  them  out  for  exercise, 
and  it  is  said  that  this  confinement  has  apparently  no  effect 
upon  the  quantity  and  quality  of  milk.  But  a  proportion- 
ately large  number  of  their  cows  are  infested  with  tubercu- 
losis. Whether  this  is  due  to  lack  of  fresh  air  and  exercise,  the 
authors  cannot  say. 

Too  much  exercise  is  adverse  to  producing  the  most  and 
best  milk.  If  a  cow  is  kept  in  the  barn  every  day,  half  an 
hour's  exercise,  preferably  out  of  doors,  when  weather  permits, 
seems  to  give  good  results.  A  small  box-stall  for  each  cow,  or 
a  well-bedded  shed  for  them  to  stand  or  lie  down  in  after  feeding, 
are  favorable  conditions  for  getting  the  proper  amount  of 
exercise,  especially  during  cold  weather. 

Change  of  location,  fright,  sudden  shocks,  and  nervousness 
are  conditions  from  which  the  cow  must  be  kept,  in  order  to 
do  her  best  as  a  milk-producing  animal. 


CHAPTER  VII. 
RECEIVING,  SAMPLING,  AND  GRADING  MILK  AND    CREAM. 

Receiving  and  Grading  of  Milk  and  Cream.  —  The  man 
who  receives  and  samples  milk  at  a  creamery  should  be 
accurate  and  quick  with  figures,  have  ability  to  grade  and 
select  milk,  and  to  stimulate  interest  in  the  production  of 
good  milk.  He  should  also  be  able  to  reconcile  and  satisfy 
patrons.  The  method  employed  in  some  creameries  of  allowing 
a  boy  with  immature  judgment  to  weigh  and  sample  milk 
should  not  be  tolerated.  The  person  who  weighs  and  samples 
milk  and  cream  comes  in  direct  contact  with  the  patrons. 
Therefore,  he  is  a  strong  factor  in  preserving  the  best  interests 
of  the  creamery.  In  many  of  the  best  butter  and  cheese  factories 
in  the  country  the  head  maker  or  manager  in  charge  is  usually 
found  at  the  weighing  can.  This  gives  him  the  opportunity 
of  studying  the  raw  material  from  which  he  is  expected  to  make 
a  high  grade  of  butter  or  cheese.  Some  of  our  large  central 
plants  pay  the  highest  salary  to  the  man  who  has  the  ability 
to  properly  grade  the  cream  and  prepare  the  starters.  This 
requires  a  fine  sense  of  smell  and  taste,  which  is  not  possessed 
by  every  one. 

The  first  step  in  the  receiving  of  milk  is  to  ascertain  the 
quality  of  the  milk  delivered  by  the  patrons.  It  is  now  a 
recognized  fact  that  the  best  butter  cannot  be  produced  from 
defective  or  abnormal  milk  or  cream,  no  matter  how  many 
improved  methods  are  employed  in  the  manufacture.  In  view 
of  this,  and  the  knowledge  we  now  have  of  the  transmission 
of  undesirable  germs  from  one  sample  of  milk  to  another,  and 
also  the  probability  that  some  of  the  patrons  will  deliver  poor 

77 


RECEIVING,  SAMPLING,  AND  GRADING.  79 

milk,  it  is  essential  that  the  milk  or  cream  be  graded  when  it 
is  delivered  at  the  creamery. 

In  the  grading  of  milk  or  cream,  different  methods  can  be 
used  for  detecting  abnormal  milk:  (1)  through  the  senses, 
taste,  sight,  and  smell;  (2)  by  the  acid  tests;  (3)  by  the  fer- 
mentation test;  (4)  by  heating;  (5)  by  the  Babcock  test  and 
the  lactometer. 

i.  Detection  of  Abnormal  Milk  through  the  Senses. — In  order 
to  detect  the  different  kinds  of  defective  milk,  one  must  be 


FIG.  24. — The  Twentieth-century  can-washer. 

endowed  with  acute  senses  of  smell,  taste,  and  sight.  When 
the  milk  is  in  a  good  condition,  it  has  a  pleasant  smell  and 
sweet  taste,  and  appears  normal.  If  it  has  a  disagreeable 
smell  and  taste  it  cannot  produce  good  butter  or  cheese.  As 
a  rule,  the  quantity  of  defective  milk  brought  into  the  aver- 
age creamery  is  much  in  excess  of  that  of  really  perfect  milk. 
As  a  consequence  it  would  not  be  practical  to  separate  all 
the  defective  milk  into  one  class  and  the  perfect  into  another. 
The  question  as  to  where  the  line  should  be  drawn  between 
the  good,  medium,  and  very  bad  milk  or  cream,  must  depend 


80  BUTTER-MAKING. 

upon  the  judgment  of  the  receiver,  and  in  a  great  measure 
upon  the  local  conditions.  Some  of  the  creameries  have  no 
facilities  for  handling  different  grades  of  milk,  and  some  sell 
butter  on  a  market  where  no  sharp  distinction  is  made  between 
good  and  poor  butter.  Others  have,  through  experience,  sat- 
isfied themselves  that  under  American  creamery  conditions 
it  does  not  pay  to  make  too  many  grades,  nor  does  it  pay  to 
grade  too  closely.  Two,  or  at  the  most  three,  grades  of  but- 
ter can  at  times  be  manufactured  in  one  creamery  profitably. 
It  is  advisable  to  reject  sour  and  abnormal  milk.  If  accepted, 
it  should  not  be  mixed  with  the  remainder  of  the  milk,  as  it 
might  contaminate  all  of  it;  or,  the  sour  milk  might  cause 
coagulation,  and  thereby  clog  up  the  separators.  If  a  can  of 
milk  is  sour,  but  otherwise  clean,  it  is  not  necessarily  unfit 
for  the  production  of  first-class  butter.  If  retained  until  after 
the  sweet  milk  has  been  skimmed,  it  may  be  run  through 
the  separator  successfully. 

2.  The  Use  of  Acid  Tests. — Some  creameries,  especially 
the  larger  central  cream  plants,  are  now  grading  the  milk  or 
cream  according  to  the  amount  of  acid  it  contains.  For  instance, 
cream  or  milk  containing  .2%  acid  or  less  is  classed  as  first 
grade;  that  containing  from  .2  to  .4%  as  second  grade,  and 
the  cream  containing  more  than  .4%  acid  as  third  grade. 
Mann's  and  Farrington's  acid  tests  can  both  be  used,  but  a 
more  rapid  and  convenient  way  is  to  use  a  solution  prepared 
from  Farrington's  tablets.  The  solution  is  prepared  by  taking 
one  tablet  for  each  ounce  of  warm  water  and  allowing  the 
tablets  to  dissolve.  When  one  part  of  this  alkaline  solution 
and  one  part  of  milk  are  put  together  in  a  cup  and  mixed 
and  the  solution  still  retains  a  pink  color,  it  shows  that  there 
is  less  than  .1%  acid  in  the  sample  tested.  If  two  parts  of 
alkali  and  one  part  of  milk  are  mixed  and  the  mixture  remains 
pink,  then  there  is  less  than  .2%  of  acid.  If  the  mixture  turns 
colorless,  it  shows  there  is  more  than  .2%  acid  in  the  sample. 
If  three  measures  of  alkali  to  one  measure  of  milk  are  taken, 
and  the  mixture  remains  pink,  that  indicates  that  there  is 


RECEIVING,  SAMPLING,  AND  GRADING.  81 

less  than  .3%  of  acid,  etc.  By  means  of  such  a  test  the  acidity 
can  quickly  be  determined. 

The  sample  cups  should  be  numbered  to  correspond  with 
the  number  of  each  patron.  The  results  of  the  tests  should 
be  noticed  at  once,  as  the  action  of  the  atmosphere  affects 
the  color. 

The  acid  tests  are  of  value  in  grading  cream,  as  a  sour 
sample  of  milk  or  cream  is  either  old  or  has  been  improperly 
kept  and  handled.  The  number  of  grades  of  cream  and  milk 
and  the  maximum  limit  of  acid  each  grade  can  contain,  are 
factors  which  must  be  decided  according  to  local  conditions, 
by  the  operator. 

3.  Use  of  the  Fermentation  Tests. — Curdled,  ropy,  red  and 
blue  milk  can,  as  a  rule,  readily  be  detected  without  the  appli- 
cation of  a  special  test,  but  there  are  cases  when  a  person's 
senses  are  not  sufficiently  acute  to  detect  samples  of  milk 
containing  undesirable  fermentations.  Several  instances  have 
recently  come  within  the  authors'  notice.  A  neighboring 
creamery  was  infested  with  a  peculiar  fermentation  that 
caused  a  very  rank  flavor  in  the  butter.  The  milk  that  came 
to  the  creamery  was  carefully  examined,  but  without  locating 
the  source  of  the  trouble.  The  cause  could  not  be  ascertained 
without  the  use  of  the  fermentation  test. 

It  is  in  such  instances  that  a  fermentation  test  is  of  special 
value.  As  a  rule,  at  least  when  the  trouble  first  begins,  it  is 
milk  from  one  particular  patron  that  causes  the  trouble.  This 
milk  may  appear  to  be  normal,  and  yet  contain  germs  which 
are  very  undesirable  for  the  manufacture  of  the  best  quality 
of  butter. 

Fermentation  Te  ts. — There  are  two  tests  which  may  be 
of  general  use;  namely,  the  "  Wisconsin  Curd  Test "  and 
the  "  Gerber  Fermentation  Test."  The  former  is  used  in 
cheese  factories,  but  the  latter  is  to  be  recommended  in  testing 
milk  for  butter-making. 

Gerber  Test. — This  test  consists  of  properly  made  glass 
tubes  which  fit  into  a  rack.  This  rack,  containing  the  bottles, 


82  BUTTER-MAKING. 

fits  into  a  small  round  tin  tank,  which  is  kept  about  two-thirds 
full  of  water.  The  temperature  of  this  water  can  be  con- 
trolled by  means  of  a  lamp  kept  burning  underneath,  or  by 
the  use  of  steam.  The  milk  from  the  different  patrons  is 
put  into  the  glass  tubes,  and  these  tubes  numbered  so  as  to 
indicate  to  which  patron  each  belongs.  The  temperature 
should  be  kept  at  about  104  to  106°  F.  for  about  six  hours. 
Then  the  tubes  are  taken  out,  the  milk  shaken,  and  the  appear- 
ance, smell,  and  taste  of  the  milk  noted.  The  tubes  are  warmed 
again  for  about  another  six  hours,  when  they  are  again  examined. 
If  any  samples  contain  a  preponderance  of  abnormal  ferments, 
the  fact  will  usually  appear  in  less  than  eighteen  hours.  If 
milk  does  not  coagulate  in  twelve  hours,  or  become  abnormal 
in  some  way,  it  is  supposed  to  be  good. 

The  special  apparatus  mentioned  above  is  not  absolutely 
essential,  nor  is  the  temperature  employed  considered  by  the 
authors  to  be  the  most  suitable  to  give  reliable  results.  Ordi- 
nary sample  jars  can  be  used,  instead  of  specially  prepared  tubes. 
After  the  milk  has  been  placed  in  the  jars  they  can  be  kept 
in  any  convenient  place,  at  a  temperature  of  about  98°  F. 
The  best  place  to  keep  them  is  in  a  vessel  containing  water, 
the  temperature  of  which  can  be  controlled. 

Wisconsin  Curd  Test. — This  test  consists  of  taking  some 
milk  in  a  jar  and  adding  about  ten  drops  of  rennet,  which 
coagulates  the  milk.  The  sample  is  allowed  .to  stand  until 
the  curd  hardens,  then  it  is  cut  into  small  pieces  with  a  case 
knife;  the  whey  is  drawn  off,  and  the  curd  allowed  to  stand 
at  a  temperature  of  98°  F.  If  there  are  any  undesirable  forms 
of  bacteria  present,  they  will  reveal  themselves  by  developing 
small  holes  in  the  curd,  usually  accompanied  by  a  bad  odor. 

This  test  is  a  very  ingenious  one  for  cheese-making.  In 
butter-making  the  Gerber  Fermentation  Test,  or  a  similar  one, 
is  more  convenient. 

4.  Grading  Milk  by  Heating. — This  test  is  not  used  very 
much  in  creameries;  but  in  cheese  factories  the  heating  of 
milk  in  order  to  ascertain  its  suitability  for  cheese-making  is 


RECEIVING,  SAMPLING,  AND  GRADING. 


83 


practised  to  a  considerable  extent.  This  test  is  in  common 
use  in  Canada.  It  consists  of  heating  a  small  sample  of  the 
milk  to  be  tested  to  120°  F.  If  it  will  stand  this  temperature 
without  coagulating,  it  is  considered  to  be  good  milk.  If  it 


FIG.  25 — Troemner's  Babcock  cream-testing  scales. 


FIG.  26. —  Tortion  cream  test- 
ing scales. 


FIG.  27. — Troemner's  Bab 
cock  cream-testing  scales. 


coagulates  when  heated  to   this  temperature,   it  is  too  sour 
to  be  used  for  cheese. 

This  heating  may  be  considered  an  acid  test.  When  milk 
contains  about  .3%  acid,  it  usually  coagulates  when  heated. 
It  should  be  borne  in  mind  in  this  connection  that  different 
samples  of  milk  do  not  coagulate  when  containing  exactly  the 
same  amount  of  acid,  and  at  the  same  temperature.  Some 
samples  will  coagulate  upon  heating  when  containing  little 


84 


BUTTER-MAKING. 


less  than  .3%  acid,  while  others  will  not  coagulate  until  more 
than  .3%  acid  has  developed. 

In  practice  the  temperature  (120°  F.)  is  not  always  considered. 
A  small  portion  of  the  sample  to  be  tested  is  put  into  a  tin  cup. 
The  cup  containing  the  milk  is  put  into  hot  water  or  over  a  jet 
of  steam.  When  hot  its  characteristics  are  noticed. 

5.  Use  of  Babcock  Test  and  Lactometer. — These  tests  are 
of  special  value  in  detecting  watered  or  skimmed  milk.  When- 


FIG.  28. — Acid  carboy  trunnion.  FIG.  29. — Acid  hydrometer. 

ever  a  sample  of  milk  appears  watery  or  blue,  it  is  fair  to  presume 
that  water  has  been  added.  The  test  for  specific  gravity  and 
the  test  for  fat  can  then  be  applied  to  such  samples  of  milk. 
As  a  rule  composite  samples  are  taken  daily  at  creameries,  and 
the  patrons  paid  according  to  the  fat  delivered.  For  this 
reason  water  adulteration  is  not  very  common  at  creameries, 
but  is  practiced  to  a  greater  extent  in  the  milk-supplies  of 
cities.  The  use  of  the  lactometer  in  connection  with  the  Bab- 
cock  test  has  already  been  referred  to  under  the  heading  of 
"Specific  Gravity  of  Milk." 


RECEIVING,  SAMPLING,  AND  GRADING. 


85 


There  are  two  tests  commonly  used  for  determining  fat  in 
milk,  viz.,  the  Babcock  and  Oil-test  Churn.  The  latter  method 
is  rapidly  giving  way  to  the  former.  The  Babcock  test  is  un- 
doubtedly superior,  though  many  still  prefer  the  0.' I- test. 


FIG.  30. — 17.6  c.c.  milk     FIG.  31. — Automatic 
pipette.  17.6  c.c.  pipette. 


FIG.  32. — Automatic 
Russian  pipette. 


The  Babcock  method  of  testing  consists  of  taking  18  grams  of 
the  substance  to  be  tested  into  a  special  graduated  bottle  as 
shown  in  illustration.  Milk  is  measured  out  with  a  pipette  hold- 
ing 17.6  c.c.  Cream,  butter,  and  cheese,  or  any  other  substance 
which  cannot  be  measured  accurately,  should  be  weighed. 
The  measured  quantity  of  milk  in  the  bottle  is  then  digested  by 
adding  17.5  c.c.  of  commercial  sulphuric  acid  having  a  specific 
gravity  of  about  1.82.  The  acid  digests  all  proteids  and  sets 


86 


BUTTER-MAKING. 


free  the  fat.    The  contents  of  the  bottle  should  be  well  shaken 
at  once  after  the  acid  has  been  added. 

The  bottle  with  its  contents  is  then  whirled  about  five 
minutes  in  a  centrifugal  machine  at  a  rate  depending  upon  the 
diameter  of  the  machine,  usually  about  850  to  1000  revolutions 


FIG.  33.  FIG.  34.  FIG.  35.  FIG.  36. 

Skim-milk          Whole-milk        Cream  test-     9-gram  cream 
test-bottle.          test-bottle.  bottle  test-bottle. 

BABCOCK  TEST-BOTTLES. 


FIG.  37. 

Cream 

test-bottle. 


per  minute.  .  The  machine  is  then  stopped  and  filled  to  the 
neck  of  the  bottle  with  pure  hot  water.  Distilled  water  is 
preferred.  The  bottles  are  then  whirled  two  minutes,  and 
hot  water  added  again  until  the  fat  rises  in  the  neck  where  it 
can  be  read.  The  bottles  are  then  whirled  again  for  about  one 
minute.  The  machine  is  then  stopped  and  the  fat  read  in 
percentage  direct  from  the  bottle.  By  using  a  pair  of  dividers 


RECEIVING,  SAMPLING,  AND  GRADING. 


87 


the  reading  may  be  facilitated.     The  temperature  at  the  time  of 
reading  should  be  between  120°  and  140°  F. 

There  are  three  very  common  defects  in  the  clearness  of  fat 
reading:  (1)  The  fat  contains  black,  charred,  flocculent  matter 
at  the  bottom  of  the  fat  column.  This  is  commonly  caused  by 


J 


3  j 

O    o 


FIG.  38. 
Wagner's  skim- 
milk  bottle. 


FIG.  39. 
Ohlson's  skim- 
milk  bottle. 


(Both  with  pneumatic  fat- 
indicator  (pat.).) 


FIG.  40. 

Butter  test-bottle,  and 

funnel  which  holds 

about  9  grams  of 

butter. 


FIG.  41. 

Russian  Babcock 
test-bottle  and 
reading-tube. 


using  too  much  or  too  strong  acid  or  mixing  milk  and  acid  at  too 
high  a  temperature.  The  remedy  is  to  use  less  acid  or  to 
cool  milk  and  acid  before  mixing.  The  black  charred  matter 
may  also  be  due  to  allowing  the  acid  to  stand  in  contact  with 
the  milk  too  long  a  time  before  mixing  or  by  pouring  acid 
through  the  center  of  the  milk.  (2)  There  may  be  a  layer  of 
white  flocculent  matter  at  the  bottom  of  the  fat  column.  This 
is  due  to  not  having  used  enough  acid  or  to  the  temperature  of 
milk  and  acid  being  too  low  or  to  not  mixing  the  acid  and  milk 


88 


BUTTER-MAKING. 


Acid  measure. 


FIG.  42. — Acid  dipper.      FIG.  43. — Combined  acid  bottle. 


FIG.  44. —Automatic  acid  pipette.        FIG.  45. — Wagner's  acid  siphon. 


RECEIVING   SAMPLING,  AND  GRADING.  89 

thoroughly.  The  remedy  is  to  use  more  acid,  or  to  warm  milk 
and  acid  before  mixing,  or  to  shake  the  mixture  thoroughly 
before  whirling.  (3)  Occasionally  there  is  a  layer  of  impure 
foam  at  the  top  of  the  fat  column.  This  is  generally  due 


FIG.  46. — The  oil-test  churn. 

to  the  use  of  hard  and  impure  water.  The  remedy  is  to  use 
pure  distilled  hot  water.  For  more  detailed  information  on 
this  subject  see  "Testing  Milk  and  its  Products/' by  Farrington 
and  Woll. 

Necessity  of  Good  Milk.— All  authorities  agree  that  the  best 
grade  of  butter  and  cheese  cannot  be  made  from  sour  or  tainted 
milk.  The  two  countries  renowned  for  the  excellence  of  their 


90 


BUTTER-MAKING. 


dairy  products — Denmark  and  Canada — owe  their  success 
largely  to  the  purity  of  the  milk  furnished  by  their  patrons. 
Makers  who  have  won  for  themselves  national  reputation  in 
cheese-  and  butter-making  have  almost  invariably  been  men 
who  insisted  OD  getting  first-class  milk..'  Badly  tainted  milk 


FIG.  47. — Wizard  tester. 

should  not  be  manufactured  into  food.  The  method  of  classify- 
ing milk  and  cream  and  paying  for  each  according  to  quality 
has  been  adopted  by  some  creameries,  especially  by  some  of 
the  large  central  plants.  The  object  of  this  is  to  induce  those 
patrons  who  are  sending  poor  milk  or  cream  to  furnish  a  better 
grade.  It  seems  more  practical  with  milk  than  with  cream, 
because  the  average  maker  dislikes  to  reject  a  can  of  cream, 


RECEIVING,  SAMPLING,  AND  GRADING. 


91 


owing  to  the  loss  the  patrons  would  sustain.  If  such  cream  is 
received,  it  should  be  churned  separately,  and  the  butter  marked 
and  sold  on  its  merits.  The  practice  of  taking  in  poor  milk 
and  cream  should  be  discouraged.  One  of  the  authors  has 
come  in  contact  with  many  patrons  in  different  parts  of  the 


FIG.  48. — Speed  indicator.      FIG.  49.— Twentieth-century  hand  tester. 


FIG.  50. — Russian  Babcock  tester. 

country  and  has  yet  to  find  the  first  patron  who  seriously 
objected  to  taking  his  milk  back  home  when  he  was  thoroughly 
convinced  that  it  was  not  in  good  condition.  Patrons  as  a 
rule  respect  the  maker  who  keeps  his  creamery  in  a  good  sanitary 
condition  and  insists  on  getting  good  milk.  It  should  be  the 
aim  of  every  creameryman  to  make  the  highest  grade  of  butter 
possible. 


92 


BUTTER-MAKING. 


FIG.  51. — Babcock  test  traveling  outfit. 


FIG.  52. — The  Agos-  steam  tester. 


RECEIVING,  STAMPING,  AND  GRADING. 


93 


Sampling  of  Milk. — The  sampling  of  milk  and  cream  for 
fat  tests  is  one  of  the  most  delicate  problems  with  which  the 
creamery  operator  has  to  deal.  If  a  proper  sample  is  not 
obtained,  the  ultimate  test  will  not  be  correct,  no  matter  how 
carefully  the  succeeding  steps  may  be  carried  out.  There  are 
two  methods  of  sampling  in  use:  First,  sampling  with  a  small 
dipper,  and  second,  sampling  with  a  sample-tube,  or  milk- 


FIG.  53. — Danish  milk-wagon.     (N.  Y.  Produce  Review.) 

thief.  The  sampling  of  milk  for  composite  samples  should  be 
done  every  day,  and  the  samples  taken  should  represent  the 
average  quality  and  form  a  certain  proportionate  part  of  the 
milk  or  cream  delivered. 

In  order  to  get  a  sample  which  represents  the  average  quality, 
the  milk  or  cream  delivered  must  be  thoroughly  stirred,  so  as 
to  get  an  even  distribution  of  the  fat. 

In  order  to  get  a  proportionate  part  of  the  milk  or  cream 
delivered  from  day  to  day,  it  is  necessary  to  use  a  sampling- 
tube. 

The  sampling  of  milk  or  cream  with  a  dipper  for  composite 
samples  has  been  in  use  so  long  that  this  method  has  become 


94 


BUTTER-MAKING. 


very  general.  If  composite  samples  are  not  kept,  and  the 
testing  of  each  patron's  milk  is  done  every  day,  the  dipper 
method  of  sampling  answers  the  purpose.  If  thick  cream  is 
being  delivered,  the  dipper  may  be  found  to  work  better  than 
the  sampling-tube,  as  the  cream  in  some  cases  may  be  so  viscous 
that  it  will  adhere  to  the  sides  and  ends  of  the  tube,  and  in 
that  way  prevent  the  cream  from  entering.  The  sampling- 
tube  may  also  retain  some  of  the  thick  cream  on  the  inside 
and  if  not  rinsed  out  properly  each  time,  the  adhering  cream 


FIG.  54. — Delivering  milk  in  Santiago.    (Farmers'  Bulletin  ) 

is  likely  to  interfere  with  getting  a  fair  sample  of  the  succeeding 
lot.  If  the  sampling-tube  is  rinsed  in  hot  water  each  time,  this 
probable  mistake  will  be  obviated. 

Sampling-tube.  —  At  creameries  where  milk  is  received, 
the  sampling-tube,  or  milk-thief,  gives  the  best  results  and 
satisfaction.  It  is  very  difficult  in  practice  to  get  a  propor- 
tionate sample  with  a  dipper,  from  day  to  day.  To  illustrate: 
A  patron  who  delivers  200  pounds  of  milk  testing  3^  fat  one 
day  may  on  another  day  deliver  100  pounds  of  milk  testing 
5%  fat.  If  a  dipperful  is  taken  from  each  for  a  composite 


RECEIVING,  SAMPLING,  AND  GRADING. 


95 


sample,  the  test  of  that  composite  sample  will  be  3 +  5 -^-2, 
or  4%.  According  to  this  test,  these  300  pounds  of  milk 
delivered  will  contain  12  pounds  of  butter-fat.  In  reality 
6  pounds  of  fat  were  delivered  in  the  200  pounds,  and  5  pounds 
of  fat  in  the  100  pounds,  making  a  total  of  11  pounds  of  fat. 
Thus  we  see  that  the  dipper  method  is  not  reliable,  and  in  this 


-80 
-70 
-00 
-50 
-10 
-30 

-20 
-rlO 


FIG.  55. — The  McKay  cream  and         FIG.  56. — Cream  sampling-tube, 
milk  sampler. 

case  the  patron  was  paid  for  1  pound  of  butter-fat  too  much 
for  the  two  days'  delivery.  If  the  sample  taken  from  the 
200  pounds  of  milk  had  been  twice  as  great  as  that  taken  from 
the  100  pounds  of  milk,  then  the  composite  test  would  have 
been  perfect,  no  matter  whether  it  had  been  taken  with  a 
dipper  or  with  a  sampling-tube.  If  the  same  weighing-can 
is  used  every  day,  then  an  exact  proportion  for  a  sample  can  be 


96  BUTTER-MAKING. 

maintained,  if  the  sampling-tube  is  put  down  perpendicularly 
into  the  milk  every  day  at  the  same  place  in  the  weighing-can 
and  otherwise  carefully  taken. 

In  case  the  cream  is  being  collected  from  different  patrons 
by  a  hauler,  a  milk-thief  often  works  unsatisfactorily.  This 
is  especially  true  during  cold  weather.  A  cream  tube  similar 
to  the  one  shown  in  the  accompanying  illustration  is  more 
effective.  The  way  in  which  the  tube  is  used  is  apparent  from 
the  figure.  If  a  certain  patron  has  40  pounds  of  cream,  the 
cream  is  filled  to  the  40  mark  on  the  scale  of  the  tube.  If  he 
has  30  pounds,  it  is  filled  to  the  30  mark,  etc. 

Sampling  Churned  Milk. — It  occasionally  happens  that  the 
milk  arrives  at  the  creamery  slightly  churned.  This  is  espe- 
cially the  case  during  the  summer.  Usually  such  milk  is 
sampled  in  this  condition,  but  if  it  is  desired  to  find  the  per- 
centage of  fat  in  such  milk  in  its  unchurned  condition,  it  is 
essential  to  melt  the  churned  fat  before  sampling.  If  the 
butter  has  been  churned  into  a  few  large  lumps,  these  lumps 
can  be  taken  out  in  a  pan,  or  pail,  with  a  comparatively  small 
amount  of  milk,  and  this  heated  until  the  butter  has  melted. 
Then  this  is  remixed  with  the  milk  from  which  it  was  first 
taken,  and  sampled  while  it  is  being  stirred. 

The  churning  of  the  milk  during  transit  is  mainly  due  to 
two  things:  First,  to  a  high  temperature  of  the  milk  (65°  to 
85°  F.),  and  secondly,  to  hauling  partly  filled  cans  a  long  distance 
over  rough  roads.  If  the  temperature  of  the  milk  is  low  (about 
50°  F.),  when  it  leaves  the  producer,  then  there  is  seldom  any 
danger  of  having  churned  milk  at  the  creamery. 

Frozen  Milk. — When  milk  is  cooled  to  31°  F.,  or  below,  the 
milk  freezes.  Ice  forms  near  the  sides  and  bottom  of  the  can, 
until  a  funnel-shaped  cavity  filled  with  milk  is  left  in  the  center. 
According  to  both  Richmond  and  Fleischmann,  the  icy  por- 
tion contains  more  water  than  the  unfrozen  milk,  and  the 
unfrozen  portion  is  rich  in  solids.  According  to  Farrington, 
when  25%  of  the  sample  of  milk  was  frozen,  the  icy  portion 
contained  about  1%  less  fat  than  the  original  portion.  When 


RECEIVING,  SAMPLING,  AND  GRADING.  97 

about  half  of  it  was  frozen   there  was   no  great  difference  in 
the  fat-content  of  the  frozen  and  unfrozen  parts. 

In  practice,  however,  it  seems  to  be  different.  When  a 
can  full  of  partly  frozen  milk  is  sampled  at  the  creamery,  the 
unfrozen  milk  nearly  always  contains  less  fat  than  the  original 
sample.  This  can  be  accounted  for  by  opening  the  can  of 
milk  and  noting  the  amount  of  frozen  cream  on  the  sides  near 
the  top.  Whether  the  unfrozen  portion  contains  less  or  more 
fat  than  the  original  depends,  therefore,  upon  conditions.  At 
any  rate,  frozen  milk  has  a  composition  different  from  that 
of  the  original  sample.  On  this  account  an  accurate  sample 
cannot  be  had,  unless  the  frozen  portion  be  first  completely 
melted  and  well  mixed  with  the  remainder. 

Sour  and  Coagulated  Milk. — In  order  to  get  a  fair  sample 
from  a  can  of  sour  and  coagulated  milk,  it  must  be  stirred 
very  thoroughly,  so  as  to  bring  the  coagulated  milk  into  a 
uniform  emulsion.  A  better  sample  can  usually  be  obtained  with 
a  dipper.  If  the  milk  is  not  too  thick,  a  fair  sample  can  be 
obtained  by  the  use  of  the  sampling-tube.  In  order  to  reduce 
a  can  of  coagulated  milk  to  a  thoroughly  uniform  quality,  it 
is  best  to  pour  it  from  one  can  into  another.  This  mixes  it 
much  more  completely  than  if  the  sample  were  simply  stirred 
with  a  dipper  or  any  other  kind  of  an  agitator. 

Apportioning  Skimmed  Milk. — The  amount  of  skimmed 
milk  to  be  received  by  the  patron  depends  largely  upon  the 
thickness  of  cream  skimmed,  and  upon  the  amount  of  skimmed 
imilk  retained  at  the  creamery  for  various  purposes.  The 
amount  of  skimmed  milk  generally  returned  by  creameries 
raries  between  80  and  90%  of  the  whole  milk  delivered. 

Most  up-to-date  creameries  now  make  use  of  skimmed - 
nilk  weighers.  Where  such  are  employed  the  man,  who  receives 
he  milk,  hands  each  patron  a  check  for  the  amount  of  milk 
lelivered.  This  check  is  put  into  the  skimmed-milk  weigher, 
,nd  it  allows  an  amount  of  skim-milk  to  flow  out,  corre- 
ponding  to  the  number  of  pounds  indicated  on  the  check. 

In  case   a  skimmed-milk  weigher  is  not    employed,  it  is 


98 


BUTTER-MAKING. 


essential    to  have   a  man    at    the    skim-milk    tank    to  weigh 
out  the  proper  amount  of  skimmed  milk  to  each  patron.    If 


FIG.  57. — Check-rack. 

the  patrons  are  allowed  to  weigh  out  their  own  skimmed  milk, 
mistakes  are  frequently  made,  which  result  in  more  or  less 
dissatisfaction.  It  is  quite  customary  for  butter-makers  to 


FIG.  58. — The  Ideal  skim-milk  weigher. 

draw  a  chalk  line  on  the  outside  of  the  can  some  distance 
below  the  surface  of  the  milk.  This  indicates  the  point  to 
which  the  can  may  be  filled  with  skimmed  milk. 


CHAPTER  VIII. 

COMPOSITE  SAMPLES. 

Definition. — In  order  to  avoid  testing  each  patron's  milk 
or  cream  every  day  for  fat,  a  small  sample,  which  represents 
the  average  quality  and  a  proportionate  part  of  the  whole,  is 
taken  from  each  patron's  milk  every  day  and  placed  in  a  jar. 
A  preservative  of  some  kind  is  previously  added,  which  keeps 
it  from  spoiling.  This  is  called  a  composite  sample. 

When  to  Sample. — Some  makers  prefer  to  sample  the  milk 
or  cream  delivered  every  day;  others  prefer  to  sample  every 
other  day.  Some  creamery  operators,  again,  sample  four  or 
five  times  in  succession  at  intervals,  the  patrons  being  unaware 
of  the  time  when  the  sampling  is  to  take  place.  The  most 
reliable  and  practical  method,  however,  is  to  take  a  sample 
every  day,  and  test  it  for  fat  at  the  end  of  every  two  weeks. 
When  cream  is  received  it  is  not  reliable  to  take  composite 
samples. 

Kind  of  Preservative  to  Add. — A  number  of  different  pre- 
servatives are  now  in  use,  and  different  ones  are  being  recom- 
mended for  creameries  and  cheese  factories  by  various  authori- 
ties. Even  a  few  of  the  best  authorities  differ  as  to  which 
one  of  the  preservatives  gives  the  best  results. 

Among  the  most  common  of  the  milk  preservatives,  and 
less  poisonous  than  certain  others,  are  salicylic  acid,  borax, 
boracic  acid,  and  bicarbonate  of  soda.  Among  the  more  vio- 
lent poisons  and  strong  preservatives  are  formaldehyde  and 
its  compounds,  chloroform,  corrosive  sublimate,  and  bichromate 
of  potash.  Bichromate  of  potash  and  corrosive  sublimate  are 
the  two  most  commonly  used  in  preserving  composite  samples. 
The  former  is  recommended  highly  by  Farrington  &  Woll  on 

99 


100  BUTTER-MAKING. 

account  of  its  relative  harmlessness,  its  cheapness,  and  efficiency. 
While  bichromate  of  potash  is  relatively  efficient  in  its 
preservative  effect,  and  not  so  poisonous  as  some  of  the  others, 
it  does  not  give  as  general  satisfaction  as  does  corrosive  sub- 
limate (mercuric  chloride),  unless  relatively  greater  precau- 
tions are  taken.  If  the  composite  samples  preserved  with 
bichromate  of  potash  are  left  standing  in  the  light  very  long, 
a  leathery  scum  forms  on  the  top,  which  is  very  difficult  to 
dissolve  in  the  sulphuric  acid.  This  is  claimed  to  be  due  to 
the  reducing  influence  of  light  on  chromate  solutions.  If  too 


FIG.  59. — Composite          FIG.  60  — Composite  samples  and  rack 
sample  bottle.  to  hold  sample  jars. 

much  bichromate  of  potash  is  added,  the  sulphuric  acid  added 
digests  the  curd  with  difficulty.  When  the  sulphuric  acid  is 
added  the  curd  is  precipitated  into  a  heavy,  gray-colored  coag- 
ulum,  which  dissolves  with  difficulty  in  the  acid. 

According  to  the  authors'  experience,  corrosive  sublimate 
tablets  can  be  highly  recommended.  The  tablets  contain  a 
color,  which,  when  dissolved,  colors  milk,  so  that  it  can  readily 
be  distinguished  as  not  being  fit  for  human  food.  The  tab- 
lets are  very  poisonous,  but  are  more  efficient  in  their  preser- 
vative effect  than  bichromate  of  potash.  They  can  be  obtained 
from  any  creamery-supply  house. 

During  the  winter,  when  the  samples  are  kept  comparatively 
cold,  less  preservative  is  needed  than  in  the  summer.  One 


102  BUTTER-MAKING. 

corrosive  sublimate  tablet  will  keep  a  half-pint  to  a  pint  of 
milk  or  cream  in  good  condition  for  about  two  weeks  in  summer, 
and  about  three  weeks  in  winter,  providing  the  sample  is  properly 
cared  for.  Some  makers  are  practicing  testing  at  the  end  of 
every  month  during  the  winter,  and  every  two  weeks  during 
the  summer.  Testing  at  the  end  of  every  month  saves  labor, 
but  it  is  not  a  reliable  method  to  follow  under  all  conditions, 
as  some  of  the  samples  are  likely  to  be  somewhat  impaired 
after  standing  so  long. 

Arrangement  of  Composite  Samples. — Pint  glass  jars  with 
covers  are,  so  far  as  known,  the  most  convenient  vessels  to 
use  for  composite  samples.  Shelves  should  be  arranged  in  the 
weighing-room  on  which  to  keep  the  bottles.  If  possible,  it 
is  best  to  have  them  in  a  case  closed  with  glass  sliding  doors. 
This  is  neat,  and,  if  the  glass  doors  fit  well,  the  samples  are  in 
some  measure  protected  in  case  of  quick,  unexpected  changes 
in  temperature.  These  sliding  doors  should  be  locked  when 
the  creamery  operator  is  absent  from  the  creamery,  in  order 
to  prevent  any  tampering  with  the  composite  samples. 

The  best  method  of  arranging  the  sample  jars  is  to  have  all 
the  jars  belonging  to  the  patrons  of  each  route  standing  in 
one  group,  or  on  one  shelf  together,  if  possible.  The  bottles 
are  numbered  to  correspond  with  the  number  given  each  patron 
on  the  milk  sheet.  The  name  of  the  hauler,  or  the  number 
of  the  route,  can  be  put  on  each  shelf.  The  samples  be- 
longing to  those  who  haul  their  own  milk  can  be  put  on  another 
shelf.  These  can  be  designated  as  individual  haulers.  Such  a 
classification,  when  the  bottles  are  plainly  numbered,  will  often 
prevent  the  mistakes  that  are  likely  to  occur  if  the  bottles  are 
simply  numbered  and  put  into  a  rack  together. 

Care  of  Composite  Samples. — In  the  first  place  the  jars  should 
be  kept  scrupulously  clean.  It  makes  the  test  unreliable  if 
the  jars  are  left  covered  with  milk  and  molds  round  the  neck 
from  one  month  to  another.  When  the  samples  have  been 
tested  the  jars  should  be  thoroughly  cleaned,  and,  if  necessary, 
scalded,  before  they  are  used  again.  Care  should  be  taken  to 


COMPOSITE  SAMPLES 


103 


spill  as  little  milk  as  possible  around  the  neck,  inside  as  well 
as  outside,  of  the  bottle  when  the  sample  is  put  in.  If  the 
milk  is  spilled  there,  it  makes  an  unattractive  appearance. 
Very  often  it  becomes  moldy,  and,  as  more  milk  is  added  and 
the  sample  shaken  every  day,  this  mold  gradually  extends 
down  the  sides  of  the  bottle.  This  causes  the  composite  sample 
to  be  infested  with  undesirable  growth,  and  to  spoil  sooner  than 


FIG.  62. — Testing-room  in  Model  Dairy,  St.  Louis  Exposition. 
(Chicago  Dairy  Produce.) 

it  would  if  greater  care  were  taken  in  keeping  the  milk  from 
coming  in  contact  with  the  sides  of  the  bottle,  before  coming 
in  contact  with  the  preservative. 

It  is  important  also  that  the  sample  jars  be  well  covered, 
otherwise  the  moisture  evaporates  and  causes  the  milk  or  cream 
to  dry  up.  It  also  makes  the  test  unreliable  by  increasing  the 
per  cent  of  butter-fat.  A  gentle  rotary  motion  should  be 
given  each  jar  when  a  sample  is  added  to  it  to  mix  the  cream, 
which  rises  to  some  extent  after  the  milk  has  stood  a  while. 


104  BUTTER-MAKING. 

Average  Sample. — It  is  sometimes  desirable  to  obtain  an 
average  test  of  the  milk  from  a  whole  day's  delivery.  This 
can  be  obtained  in  two  ways:  First,  by  taking  a  sample  from 
each  patron's  milk  with  a  sampling-tube,  and  putting  it  all 
together  in  one  jar.  The  result  represents  an  average  test,  pro- 
viding the  samples  have  been  correctly  taken.  Second,  an  aver- 
age test  can  be  had  by  boring  a  small  hole  in  the  conductor-head. 
When  the  milk  passes  over  this  hole,  a  small  portion  of  it 
drops  through.  A  vessel  of  some  kind  can  be  put  underneath 
to  catch  the  drops.  Such  a  drip-sample  will  represent  very 
accurately  the  average  quality  of  the  milk  received  at  the 
creamery.  If  it  is  desirable  to  keep  this  sample,  a  preservative 
can  be  added  to  it. 

Composite  Sampling  without  the  Use  of  Preservatives. — 
Pipettes  can  be  obtained  holding  5.87  c.c.  of  milk.  These  are 
one-third  the  size  of  the  ordinary  17.6  c.c.  pipette  used  for 
the  Babcock  test.  With  this  small  pipette  a  sample  may  be 
taken  every  day  from  each  patron's  milk,  during  three  suc- 
cessive days,  and  emptied  into  the  same  test-bottle  each 
day.  At  the  end  of  three  days  the  samples  may  be  tested 
and  the  bottles  cleaned,  ready  for  use  again. 

Accurate  composite  samples  may  be  obtained  in  this  way, 
providing  the  sample  in  the  pipette  is  correctly  taken  each 
day.  No  preservative  is  needed.  The  preservatives  are  added 
to  the  composite  samples  to  prevent  curdling.  The  test-bottles 
may  be  placed  on  a  shelf,  or  preferably  in  a  rack  made  to  hold 
them.  They  should  be  marked  in  such  a  way  as  to  identify 
them.  A  good  way  is  to  mark  them  the  same  as  the  com- 
posite jars,  the  number  on  the  jar  corresponding  to  the  number 
on  the  milk-sheet  for  each  patron. 


CHAPTER  IX. 
CREAMERY  CALCULATION. 

Find  the  Average  Per  Cent  of  Fat. — In  calculating  the 
average  per  cent  of  fat  from  a  number  of  cows,  or  the  milk 
furnished  by  the  different  patrons,  the  mistake  of  adding  the 
tests  of  all  the  samples  together  and  dividing  the  sum  by  the 
total  number  of  samples  tested  is  often  made.  Milk  from 
different  patrons,  or  from  different  cows,  will  always  vary, 
some  in  quality  and  some  in  quantity,  and  in  order  to  get  a 
correct  average  test,  both  quantity  and  quality  must  be  taken 
into  consideration.  The  wrong  way  of  calculating  the  average 
percentage  may  be  illustrated  as  follows : 

Sample.  Milk  Delivered.  Per  cent  Fat. 

1  50  Ibs.  5.0 

2  100    "  4.5 

3  500    "  3.0 

4  300    "  3.5 


4)16% 


The  average  test,  according  to  the  wrong  method,  =4%. 
The  correct  way  of  calculating  the  average  percentage  may 
be  illustrated  as  follows : 

Sample.  Milk  Delivered.  Per  cent  Fat. 

1  50  Ibs.  5.0=   2.5  Ibs.  fat 

2  100    "  4.5=    4.5    "      " 

3  500    "  3.0  =  15.0    "      " 

4  300    "  3.5  =  10.5    "      " 


950  Ibs.  950)32.5  Ibs.  fat 

3.42 


105 


106 


BUTTER-MAKING. 


The  average  test,  according  to  the  correct  method,  is  3.42%. 

It  will  be  seen  from  the  example  quoted  that  there  is  a 
difference  of  more  than  .5%.  If  the  percentage  of  fat  or 
the  -number  of  pounds  of  milk  is  uniform,  then  it  does  not 
matter  which  of  the  two  ways  illustrated  above  is  used.  But 
as  uniformity  in  either  of  these  respects  scarcely  ever  exists 
in  practice,  the  only  correct  way  of  calculating  the  percentage 
is  to  find  the  total  number  of  pounds  of  fat  and  divide  it  by 
the  total  number  of  pounds  of  milk;  the  result  is  .0342,  which 
may  be  written  3.42%. 


FIG.  63. — A  Russian  co-operative  creamery  in  Siberia. 
(U.  S.  Government  Bulletin.) 

It  is  very  common  for  creamery  patrons  to  test  the  milk 
from  each  of  their  cows,  then  add  the  tests  together  and  divide 
by  the  total  number  of  cows  tested.  The  result  they  will 
call  the  average  test,  and  frequently  such  tests  are  made  use 
of  as  evidence  against  a  creamery  operator  to  prove  that  his 
tests  at  the  creamery  were  not  correct.  The  fallacy  is  evident 
from  what  has  been  said  above. 


CREAMERY  CALCULATION.  107 

The  same  mistake  is  also"  likely  to  be  made  in  finding 
the  average  test  from  several  creamery-plants  and  skimming- 
stations. 

Calculation  of  Overrun. — The  amount  of  overrun  is  the 
difference  between  the  amount  of  pure  butter-fat,  and  the 
amount  of  butter  manufactured  from  that  given  amount  of 
fat.  This  difference,  divided  by  the  amount  of  fat  and  multi- 
plied by  100  will  give  the  percentage  of  overrun.  The  calcu- 
lation of  the  overrun  in  the  creamery  should  always  be  mado 


FIG.  64. — A  Cheshire  creamery,  England.     (London  Creamery  Journal.) 

from  the  fat-basis  on  which  the  patrons  are  being  paid.  If 
the  fat  is  delivered  in  the  cream,  the  overrun  should  be  calcu- 
lated from  the  fat  in  the  cream.  The  overrun  calculated  from 
the  composition  of  the  butter  manufactured  would  not  be  an 
indication  of  the  correct  overrun,  as  there  might  be  serious 
losses  of  fat  sustained  during  the  different  steps  in  the  manu- 
facture, such  as  from  inefficient  skimming,  incomplete  churning, 
and  general  losses  in  the  creamery.  It  is  possible  that  butter 
might  show  a  high  content  of  the  substances  not  fat,  and 
yet  not  show  a  good  overrun  on  account  of  losses;  while  butter 
containing  only  a  medium  high  moisture-content  might  show 
as  great  or  greater  overrun  on  account  of  thorough  and  efficient 
work  during  the  different  steps  of  manufacture. 


108  BUTTER-MAKING. 

The  amount  of  overrun  depends  upon: 

1.  Thoroughness  of  skimming. 

2.  Completeness  of  churning. 

3.  General  losses  in  the  creamery. 

4.  Composition  of  the  butter  manufactured. 

The  theoretical  overrun,  however,  may  be  quite  accurately 
calculated  from  the  composition  of  the  butter  manufactured 
in  a  well  regulated  creamery.  In  creameries  where  the  con- 
ditions of  separation  and  churning  are  almost  perfect,  the 
amount  of  fat  lost  in  the  buttermilk  and  the  skimmed  milk 
is  quite  constant  from  day  to  day,  and  should  not  exceed  .1% 
in  the  skimmed  milk  and  .2%  in  the  buttermilk,  according 
to  the  Babcock  test.  Basing  the  calculations  upon  the  above 
figures,  the  theoretical  overrun  may  be  calculated  from  the 
composition  of  the  butter  as  follows: 

If,  for  instance,  we  start  with  1000  pounds  of  milk-testing 
4%  fat,  there  will  be  a  total  of  40  pounds  of  fat.  If  we  skim 
32%  cream  from  4%  milk,  we  should  have  ¥4F,  or  \,  of  it  cream, 
and  the  remainder  skim-milk,  or  125  pounds  of  cream  and 
875  pounds  of  skimmed  milk.  If  there  were  .1%  of  fat  in  the 
skimmed  milk,  there  would  be  a  loss  of  .875  pounds  of  fat  during 
skimming.  There  would  then  be  39.125  pounds  of  fat  in  the 
125  pounds  of  cream  (40 -.875  =  39. 125).  If  10%  of  starter 
were  added  to  the  cream  we  should  get  137.5  pounds  of  cream 
testing  28.4%.  (125  pounds  cream  X  1.10=  137.5  pounds  cream; 
39.125-^137.5=28.4%  fat.)  By  churning  this  cream  we 
should  obtain  about  100  pounds  of  buttermilk.  If  it  tested 
.2%  fat  there  would  be  a  loss  of  about  .2  pounds  of  fat,  making 
a  total  loss  of  fat  in  skim-milk  and  buttermilk  of  1.075  pounds. 
Subtracting  this  total  loss  of  1.075  from  40  pounds  we  would 
have  38.925  pounds  of  fat  left  to  be  made  into  butter 
(40-1.075  =  38.925  pounds  of  fat).  If  the  butter  on  analysis 
proves  to  contain  82%  fat,  the  total  number  of  pounds  manu- 
factured will  be  38.925-^-82  =  47.47  pounds  of  butter.  47.47- 
40  =  7.47  pounds  theoretical  overrun,  and  7.47  -=-40  X 100=  18.7% 
overrun  (theoretical). 


CREAMERY  CALCULATION.  109 

It  is  evident  that  the  losses  of  fat  will  vary  according  to 
the  different  conditions.  The  richer  the  cream,  and  the  less 
fat  in  the  whole  milk  to  be  skimmed,  the  more  skim-milk  there 
will  be;  the  thinner  the  cream,  and  the  more  fat  there  is  in 
the  milk  to  be  skimmed,  the  less  skimmed  milk  there  will  be, 
and  consequently  with  the  same  skimming  efficiency  less  fat 
will  be  lost  in  the  skim-milk.  The  thinner  the  cream  is  the 
more  buttermilk  there  will  be.  These  conditions  must  be  left 
for  the  operator  to  govern  according  to  the  conditions  present. 

The  actual  amount  and  per  cent  of  overrun  as  determined 
in  creameries  is  calculated  as  described  previously.  The 
formula  is  as  follows: 

Butter-fat 
T-T X 100= per  cent  of  actual  overrun. 

Calculation  of  Churn-yield. — Instead  of  expressing  the  in- 
crease of  butter  over  that  of  fat  in  the  percentage  overrun, 
as  above,  it  is  often  customary  among  creamerymen  to  speak 
of  the  "churn-yield."  For  instance,  they  say  that  their  test 
was  3.90,  and  their  churn-yield  was  5,  meaning  that  on  the 
average  each  100  pounds  of  milk  contained  3.9  pounds  of 
fat  and  yielded  5  pounds  of  butter.  The  churn-yield  is  always 
expressed  in  percentage,  and  is  obtained  by  dividing  the  total 
pounds  of  butter  obtained  by  the  total  pounds  of  milk  from 
which  the  butter  was  made,  according  to  the  following  formula: 

Pounds  of  butter 

15 1 — e — TT~  X 100  =  churn-yield. 

Pounds  of  milk 

In  case  cream  is  handled  instead  of  milk,  the  same  may 
be  obtained  by  substituting  "pounds  of  cream"  for  "pounds 
of  milk"  in  the  formula. 

Calculation  of  Dividends.  —  The  method  of  calculating 
dividends  will  vary  according  to  the  agreements  between  the 
manufacturer  of  the  butter  and  the  milk  and  cream  producers. 


110 


BUTTER-MAKING. 


Some  manufacturers  agree  to  make  the  butter  for  so  many 
cente  per  pound  of  butter  (usually  3  or  4  cents).  Occasionally 
the  creamery  proprietor  agrees  to  pay  a  final  fixed  sum  for  milk 
delivered  containing  a  definite  amount  of  fat  (usually  4%). 
These  two  methods  are  not  in  use  much  at  the  present  time, 
although  in  the  eastern  part  of  the  United  States  the  method 
of  paying  the  operator  so  much  per  pound  of  butter-fat  manu- 
factured is  quite  common. 


FIG.  65. — Jeinsen  creamery,  Barnten  Province,  Hamburg,  Germany. 
(Creamery  Journal.) 

The  two  methods  most  commonly  used,  especially  in  the 
central  West,  are  as  follows: 

(1)  Pay  so  much  per  pound  of  butter-fat  based  upon  some 
standard   market   price,   such   as   Elgin   or   New  York.     The 
amount  paid  now  by  the  central  plants  for  butter-fat  is  usually 
2  or  3  cents  per  pound  below  "New  York  Extras,"  and  the 
company  pays  all  freight  or  express  charges. 

(2)  Pay  per  pound  of  fat  based  upon  the  net  income  of  the 
creamery. 


CREAMERY  CALCULATION.  Ill 

1.  The  former  method  of  paying  for  butter-fat  has  become 
quite  common.     Nearly  all  the  hand-separator  or  central  plants 
are  paying  for  butter  according  to  this  method.     Payments  are 
usually  made  every  two  weeks.     Although  this  causes  more 
work,  it  is  much  more  satisfactory  to  the  patrons  than  to  pay 
only  at  the  end  of  each  month. 

In  order  to  calculate  dividends  when  paid  at  the  end  of 
two  weeks  or  at  the  end  of  each  month,  the  first  step  is  to 
find  how  many  pounds  of  butter-fat  have  been  delivered  by 
each  patron.  If  composite  samples  are  taken,  and  these 
tested  for  fat  at  intervals  of  one  week,  which  would  make  about 
four  tests  during  the  month,  and  two  during  half  a  month, 
the  results  of  the  several  tests  may  be  added,  and  the  sum 
divided  by  the  number  of  samples  tested.  This  may  give  the 
average  test,  but  it  must  be  borne  in  mind  that  this  method 
is  also  likely  to  give  wrong  results.  Especially  is  this  so 
when  cream  is  delivered  which  varies  in  quantity  as  well  as 
quality  during  the  different  parts  of  the  month. 

If  cream  only  is  being  received,  it  is  a  good  plan  to  test 
each  patron's  cream  every  day,  as  it  is  more  or  less  difficult 
to  get  absolutely  accurate  composite  samples  from  creams  of 
different  richness.  Besides  this,  the  patrons  can  get  the  test 
as  well  as  the  weight  of  the  cream  of  each  previous  day's  de- 
livery, and  thus  know  how  their  account  stands  from  day  to 
day.  A  little  more  labor  is  involved  in  doing  this,  but  in  the 
long  run  it  keeps  the  patrons  better  satisfied. 

2.  If  the  price  of  butter-fat  per  pound  is  being  based  upon 
the  net  income,  as  is  the  case  in  nearly  all  co-operative  cream- 
eries, and  also  in  many  proprietary  creameries,  the  first  step 
is  to  find  out  how  much  butter-fat  each  patron  delivered  during 
the   specified   time,  —  two  weeks  or  a  month,  whichever  may 
be  the  case.    When  this  has  been  obtained,  the  total  pounds 
of  fat  delivered  by  all  the  patrons  are  found.    From  the  gross 
income  the  total  expenses  of  running  the  creamery  are  sub- 
tracted.    The  remainder  represents  the  net  income.    This  is 
then  divided  by  the  total  pounds  of  fat  delivered  to  the  cream- 


CREAMERY  CALCULATION.  113 

ery,  and  the  quotient  represents  the  price  per  pound  of  butter- 
fat  to  the  patrons. 

Knowing  the  price  of  one  pound  of  fat  to  be  paid  to  the 
patrons,  the  sum  due  to  each  patron  is  found  by  multiplying 
the  price  per  pound  by  the  total  number  of  pounds  of  fat  each 
patron  delivered  during  the  specified  time. 

In  some  instances  provisions  are  made  for  a  "sinking  fund." 
This  is  a  name  given  to  a  fund  raised  by  deducting  so  much 
per  pound  of  fat,  or  per  100  pounds  of  milk,  from  each  patron's 
delivery  at  the  end  of  each  month.  This  fund  is  for  the  pur- 
pose of  paying  off  a  debt  gradually,  or  for  raising  a  fund  for 
new  equipment,  or  other  improvements  in  the  creamery.  In 
case  such  money  is  to  be  withheld,  it  is  deducted  previous  to 
making  the  final  calculation. 

Cream-raising  Coefficient. — By  the  term  cream-raising  coeffi- 
cient we  understand  the  percentage  of  fat  removed  from  the 
milk  during  the  process  of  separation.  The  calculation  of  the 
cream-raising  coefficient  may  be  illustrated  as  follows: 

Suppose  we  have  100  pounds  of  milk  containing  4%  fat, 
and  yielding  85  pounds  of  skim-milk  and  15  pounds  of  cream, 
the  skim-milk  containing  .2%  fat. 

Total  fat  in  whole  milk  =  100  Ibs.  X4%  =4  Ibs. 
Total  fat  in  skim-milk  =  =  85  Ibs.  X.2%  =  .17  Ibs. 
Total  fat  in  cream         =     4  Ibs.  -.17  Ibs.  =3.83  Ibs. 

3  83  X 100 

— j—     =95.75%  of  the  total  4  pounds  of  fat,  or  the 

cream-raising  coefficient. 

Statement  to  Patrons. — A  complete  statement  should  be 
made  each  time  a  settlement  is  made,  and  accompanied  with 
the  check.  A  statement  similar  to  the  following  one  may 
serve  as  an  example:  * 

*  Creamery  Butter-making,  by  Michels. 


114 


BUTTER-MAKING. 
CREAMERY  COMPANY 


IN   ACCOUNT   WITH 


Mr. 


For  the  month  of 


190 


Cr. 


Dr. 


No.  pounds  milk  delivered  Pounds  butter at 

by  you       Cans,  at   .      

Average  test       Cash 

No.  pounds  butter-fat Hauling  at  ...     per  100  Ibs 

Price  per  pound       .      .       $ $ 

Balance  due  you $ 

Total  pounds  milk  delivered  at  creamery $ 

Average  test  at  creamery       

Total  pounds  butter-fat  at  creamery 

[-  -  Ibs.  at  -         $ 

Sales  of  butter  i  $ 

l <(     "  « 

~~ * 

I <i     a  ______  ® 

L  ......      <5> 

Less  —      —  cts.  for  making. 

Balance  due  patrons $ 

Per  cent  overrun 

Testing  witnessed  by 

Prest. 

Secy. 

At  the  end  of  the  year  a  final  statement  should  be  made 
by  the  respective  officers,  similar  to  the  following  one: 

ANNUAL  REPORT. 

Incorporated 190 .  .  .        Commenced  Operations, 190 . . . 

Annual  Report,  190.  . . 

of  the 

CREAMERY  COMPANY 

of , .,  Iowa. 

( Butter-maker; Asst.  Butter-maker) 

CAPITAL  STOCK  $ PAID  IN  $ 

OFFICERS  AND  DIRECTORS. 
President,        Secretary, — Treasurer. 


CREAMERY  CALCULATION.  115 

SECRETARY'S  REPORT. 

To  the  Stockholders:    Your  Secretary  herewith    submits   the    following 
report  for  the  year  ending  December  31,  190. .. 

Total  pounds  of  milk  received 

Total  pounds  butter-fat  contained  in  same 

Total  pounds  butter  manufactured 

Average  test  of  butter-fat  per  hundred  pounds  of  milk 
Average  yield  of  butter  per  hundred  pounds  of  milk. 
Average  price  paid  per  hundred  pounds  of  milk   . 
Average  price  paid  per  hundred  pounds  of  butter-fat 
Average  per  cent  increase  of  churn  over  test  (overrun) 
Average  price  received  per  pound  of  butter     . 
Average  monthly  expenses  of  running  creamery  . 
Average  co~t  of  manufacturing  butter  per  pound. 


Following  is  a  Monthly  Statement  for  the  year  190. .. 

January      

February    

March 

April 

May 

June 

July 

August 

September 

October 

November 

December  . 


Totals 


STATEMENT  OF  CASH  RECEIVED  AND  DISBURSED. 

RECEIPTS.  DISBURSEMENTS. 

Received  for  butter       .     $ Paid  to  patrons  for  milk         $ . . 

Running  expenses  of  cream- 
ery and  supplies  on  hand  .  .  . 

Paid  for  machinery,  ma- 
terial, repairs,  etc.  (out 
of  percentage  fund)  . 

Paid  dividend  on  stock  for 
190 ..  (out  of  percentage 
fund) 

Paid  dividend  on  stock  for 
190.  .  (out  of  percentage 
fund) 

Total  amount  of  cash  re-  Total    amount    of   orders 

ceived    and    paid     to  drawn  on  Treasurer    . 

Treasurer Cash  balance  in  hands  of 

Cash  balance  in  hands  of  Treasurer,  Jan.  190 

Treasurer,  Jan.  190 

Total      Total 


116  BU  TTER-MA  KING. 

TREASURER'S  REPORT. 

To  the  Stockholders  of  the Creamery  Company:    Your 

Treasurer  herewith  submits  the  following  report : 

STATEMENT  OF  CASH  RECEIVED  AND  DISBURSED. 
RECEIPTS.  DISBURSEMENTS. 

Total     Total     

Respectfully  submitted, ,  Treasurer. 

,  Cashier  of  Bank. 

REPORT  OF  AUDITING  COMMITTEE. 

To  the  Stockholders  of  the Creamery  Company: 

We,  the  undersigned,  appointed  by  your  Board  of  Directors  to  examine 
and  audit  the  Books,  Accounts,  and  Vouchers  of  the  Secretary  and  Treas- 
urer of  the Creamery  Company  for  the  year  190..  .,  hereby 

certify  that  we  have  carefully  examined  the  same  and  compared  them  with 
the  above  reports  of  said  officers,  and  find  them  correct. 

In  witness  whereof  we  have  hereunto  set  our  hands  at ,  Iowa, 

this  ....  day  of A.D.,  190.  .  .. 


Auditing  Committee. 


Paying  for  Fat  in  Cream  Compared  with  Paying  for  Fat  in 
Milk. — It  is  evident  that  when  patrons  deliver  fat  in  the  form 
of  milk  the  creamery  operator  sustains  a  loss  in  the  skimmed 
milk,  while  if  the  fat  is  delivered  in  the  form  of  cream,  no 
fat  is  lost  in  the  skim-milk  at  the  creamery,  and  consequently 
the  cream  patron  should  receive  more  per  pound  of  fat  delivered 
than  the  whole-milk  patron,  providing  the  quality  of  the  fat 
in  the  cream  is  as  good  as  that  in  the  form  of  milk.  The  butter- 
maker  should  obtain  a  larger  overrun  from  the  fat  of  the  cream 
than  he  does  from  the  fat  of  the  milk.  The  amount  which 
the  patrons  should  be  paid  for  fat,  delivered  in  the  form  of 
cream,  depends  upon  the  thoroughness  of  skimming.  If 
1000  pounds  of  milk  testing  4%  fat  were  bought  and  skimmed, 
there  would  be  a  loss  of  about  .9  of  a  pound  of  fat  during  the 
skimming,  which  would  make  about  1  pound  of  butter,  worth 
about  20  cents.  If  bought  in  the  form  of  cream  this  loss  would 
not  be  sustained.  The  above  loss,  during  skimming,  according 
to  the  figures  mentioned,  would  amount  to  about  half  a  cent 


CREAMERY  CALCULATION. 


117 


per  pound  of  butter  manufactured.  The  fat  lost  during  the 
skimming  process  would  amount  to  about  2%  of  the  total 
fat.  If  the  cream  fat  be  increased  by  2%,  an  approximate 
basis  for  paying  milk  and  cream  patrons  is  obtained. 

Degree  of  Justice  in  Paying  Cream  Patrons  More  per  Pound 
of  Fat  than  the  Milk  Patrons. — There  is  another  side  to  this 
question  of  reaching  an  equity  of  payment  between  the  cream 
patrons  and  milk  patrons.  A  cream  patron  should  not  receive 
more  pay  than  a  milk  patron,  unless  the  quality  of  the  fat 
is  as  good  as  that  delivered  by  the  milk  patron.  It  is  a  well- 
known  fact  that  the  fat  delivered  in  the  form  of  cream  is,  as 
a  rule,  and  has  been,  much  inferior  to  that  delivered  in  the 
form  of  whole  milk.  This  is  evidently  due  to  the  fact  that 
cream  is  not  delivered  daily  to  the  creamery,  and  that  it  is 
improperly  handled  on  the  farm,  and  during  transportation. 
According  to  the  results  obtained  in  the  Iowa  Educational 
Contest,  and  other  scorings,  butter  from  hand-separator  cream 
on  an  average  seldom  scores  above  90,  on  a  scale  of  100.  It  is 
safe  to  come  to  the  conclusion  that  there  is  at  least  a  difference 
of  three  points  in  quality  in  favor  of  creamery  butter  made 
from  milk-fat.  Mr.  Healy,  one  of  the  best  known  butter  judges, 
claims  that  in  the  near  future  butter  will  be  sold  more  accord- 
ing to  quality  than  it  is  now.  He  asserts  that  a  fair  basis  of 
paying  for  butter  according  to  scores  would  be  to  deduct  a 
quarter  of  a  cent  for  every  point  that  the  butter  scores  below  91, 
and  an  addition  of  a  quarter  of  a  cent  for  every  point  it  scores 
above.  This  would  make  a  difference  of  three-quarters  of  a 
cent  per  pound  in  the  selling  price  of  butter  made  from  whole 
milk  and  that  made  from  hand-separator  cream.  It  was 
figured  above  that  the  loss  from  skimming  would  amount  to 
about  half  a  cent  per  pound  of  butter,  thus  leaving  a  margin 
of  one-quarter  of  a  cent  in  favor  of  the  whole-milk  patron 
per  pound  of  butter,  rather  than  being  in  favor  of  the  cream 
patron. 


CHAPTER  X. 

HEATING  MILK  PREVIOUS    TO  SKIMMING. 

Reasons  for  Heating.— Owing  to  the  fact  that  all  separators 
will  skim  closer  and  not  clog  so  easily  when  milk  is  heated, 
nearly  all  creameries  heat  or  warm  the  milk  previous  to  skim- 
ming. By  thus  heating  and  stirring  the  milk  in  a  pure  atmo- 
sphere, many  undesirable  odors  or  taints  escape.  With  an 
increase  of  temperature;  the  viscosity  of  the  milk  is  lessened, 
due  chiefly  to  the  softening  and  separation  of  the  fat-globules. 
Such  an  increased  fluidity  of  the  milk  lessens  the  resistant 
force  of  the  fat-globules  when  exposed  to  the  centrifugal  force 
of  the  separator.  The  higher  the  temperature  the  more  fluid 
the  milk  becomes,  and  consequently  the  easier  the  fat  can  be 
separated. 

By  warming  the  milk  to  a  high  temperature  and  leaving 
it  for  some  time,  and  then  cooling  quickly  again  to  skimming 
temperature  (90°  F.)  and  separating,  the  skimming  efficiency 
of  the  separator  is  increased  materially.  If  the  milk  has  been 
standing  at  a  very  low  temperature  for  at  least  three  hours, 
and  then  is  quickly  warmed  up  to  the  usual  skimming  tem- 
perature, and  skimmed,  the  warming  of  the  milk  has  com- 
paratively little  effect  in  bringing  it  into  a  good  condition  for 
skimming.  It  will  thus  be  seen  that  it  is  possible  to  skim 
milk  at  the  same  temperature,  and  yet  get  different  results, 
due  to  previous  temperature  conditions.  Duration  of  tem- 
perature should  be  considered  as  well  as  the  temperature  itself. 

The  temperature  to  which  milk  should  be  heated  previous 
to  skimming  varies  according  to  different  investigators.  The 
temperature  that  has  been  mostly  employed  in  the  past  in 

118 


HEATING  MILK  PREVIOUS  TO  SKIMMING.  119 

this  country,  and  perhaps  at  the  present  time,  is  about  90°  F. 
This  comparatively  low  temperature  was  fixed  owing  to  the 
supposedly  bad  effect  high  skimming  temperature  had  upon 
the  body  of  the  finished  butter.  Exposing  milk,  at  high  tem- 
peratures, to  the  centrifugal  force  in  a  separator  was  said 
to  producea  greasy  body  in  butter.  According  to  some  ex- 
periments conducted  at  the  Iowa  Experiment  Station  by  the 
authors  during  the  year  1902,  milk  can  be  skimmed  at  175°  F. 
without  any  injury  to  the  quality  of  the  butter,  providing  the 
cream  is  cooled  to  ripening  temperature,  or  below,  as  soon 
as  it  has  been  skimmed.  After  the  ripening  has  been  com- 
pleted the  cream  should  be  exposed  at  least  three  hours  to  a 
low  temperature  (50°  F.)  previous  to  churning. 

If  the  milk  is  heated  in  any  of  the  best  modern  heaters, 
no  injurious  results  to  the  quality  of  the  butter  will  be  obtained. 
Prof.  Dean,  at  the  Ontario  Agricultural  College,  has  also  found 
it  practical  to  heat  to  pasteurization  temperature  previous  to 
skimming.  In  many  creameries  in  Denmark  this  method  of 
heating  milk  is  also  followed.  The  Danes,  as  a  rule,  however, 
have  the  heated  milk  pass  over  a  cooler  before  it  goes  into 
the  separator. 

The  chief  difficulty  encountered  by  the  authors  in  heating 
milk  to  such  a  high  temperature  previous  to  skimming,  was 
that  the  upper  bearing  in  the  separator  got  so  hot  that  it  was 
deemed  injurious  to  the  separator,  although  the  bearing  did 
not  heat  to  such  an  extent  as  to  cause  the  running  of  the 
machine  to  be  abnormal  in  any  way. 

Advantages  of  Warming  Milk  to  High  Heat  Previous  to 
Skimming. — The  advantages  of  heating  milk  to  a  high  tem- 
perature (175°  F.)  previous  to  skimming,  may  be  summarized 
as  follows: 

(1)  Undesirable  taints  are  eliminated  from  the  milk  to  a 
greater  extent  than  can  be  accomplished  in  any  other  way, 
without  applying  chemicals. 

(2)  The  heating  of  whole  milk  destroys  the  germs  in  the 
resultant  skimmed  milk  and   cream  practically  as  efficiently 


HEATING  MILK  PRFAIOUS    TO  SKIMMING. 


121 


as  when  heated  after  the   skimming   process    has   been  com- 
pleted. 

(3)  Less  heating  and  cooling  apparatus  is  necessary. 

(4)  Closer  skimming. 

How  Heated. — There  are  two  methods  by  which  milk  is 
heated  previous  to  skimming.  First,  by  the  use  of  direct 
live  steam;  second,  by  the  use  of  heaters  which  heat  with 
steam  or  hot  water  indirectly. 


FIG.  68. — The  Twentieth-century  milk-heater. 


Heating  of  milk  with  direct  live  steam  is  accomplished  in 
two  ways:  first,  by  entering  a  steam  hose  into  the  vat  full 
of  milk;  and,  second,  by  making  use  of  special  heaters,  which 
allow  steam  to  come  in  direct  contact  with  the  milk  as  the 
milk  passes  through. 

The  method  of  heating  milk  with  direct  live  steam  cannot 
be  too  strongly  condemned,  because  it  leaves  bad  effects  upon 
the  flavor  of  the  butter.  At  the  Milwaukee  National  Butter 
contest  in  1903,  where  over  eight  hundred  exhibitors  were 
represented,  the  authors  noticed  that  where  the  criticism 
" burnt,  oily  flavor"  was  made  on  the  score  card,  the  milk 
from  which  the  butter  was  made  had  in  most  cases  been  heated 
with  live  steam.  The  burnt  flavor  may  possibly  be  due  to  the 
sudden  excessive  heat  to  which  the  milk  will  be  exposed  when 
coming  in  contact  with  live  steam.  The  greatest  danger, 
however,  in  heating  milk  with  live  steam  is,  that  impurities 
from  the  pipes  and  boiler  are  likely  to  be  transmitted  to  the 


122  BUTTER-MAKING. 

milk,  and  cause  bad  flavors.  In  most  of  the  creameries  the 
exhaust-steam  from  the  engine  is  used  to  heat  the  water  for  the 
boiler.  This  steam  is  likely  to  carry  with  it  cylinder-oil,  which 
will  impart  undesirable  flavors  to  the  butter.  Some  creameries 
are  also  using  boiler  compounds  for  the  removal  of  scales. 
These,  when  subjected  to  high  heat  and  pressure,  are  likely 
to  be  transmitted  to  the  steam-pipes,  and  from  there  with  the 
steam  into  the  milk.  The  scale  and  rust  of  steam-pipes  are 
also  likely  to  be  transferred  to  the  milk. 

The  right  way  to  heat  milk  previous  to  skimming  is  to  make 
use  of  one  of  the  special  heaters  on  the  market,  which  heat 
by  the  use  of  steam  or  hot  water  indirectly. 


CHAPTER  XI. 

SEPARATION  OF  CREAM. 

IN  the  process  of  the  manufacture  of  butter  it  is  essential 
that  the  fat  of  the  milk  shall  be  concentrated  into  a  compara- 
tively small  portion  of  the  milk-serum.  This  concentration  of 
fat  carries  with  it  a  portion  of  all  the  other  milk  constituents, 
and  the  product  is  called  cream.  It  is  possible  to  churn  milk 
without  any  separation,  but  a  much  greater  loss  is  attendant, 
if  the  fat  is  not  brought  together  by  the  process  called  separa- 
tion. 

The  different  kinds  of  cream  may  be  classified  according  to 
the  different  methods  of  cream-separating: 

f  Shallow-pan  cream. 

I 
Cream 


I      kJlldllWY  ~|_^t*ll    ^ICCHll. 

f  Gravity  cream {  Deep-setting  cream. 

L  Water  dilution  cream  (hydraulic). 


Centrifugal  rream       /  Hand-separator  cream. 
Le  m  '  '  \  Creamery-separator  cream. 

GRAVITY  CREAMING. 

Shallow-pan  System. — This  method  of  creaming  is  used 
mostly  on  farms  which  are  situated  unfavorably  in  relation  to  a 
creamery,  or  for  some  other  reasons  do  not  send  their  milk  to 
the  creamery.  It  consists  in  placing  the  milk  in  shallow  pans, 
from  2  to  4  inches  in  depth,  as  soon  after  milking  as  possible. 
The  milk  is  then  placed  where  it  can  be  quickly  cooled  to  a 
temperature  of  at  least  60°  F.  A  lower  temperature  than  this 
is  desirable  if  conditions  permit.  The  atmosphere  in  the  room 
in  which  the  milk  is  standing  must  be  pure,  free  from  dust, 

123 


124  BUTTER-MAKING. 

draught,  and  any  undesirable  taints  or  odors,  since  it  takes 
about  thirty-six  hours  of  quiet  standing  for  the  cream  to  rise. 
If  there  is  a  constant  current  of  air  in  the  room,  a  leathery 
cream  is  likely  to  form.  At  the  end  of  this  time  the  cream  is 
removed  by  the  use  of  a  skimmer,  made  especially  for  this 
purpose.  It  is  difficult,  however,  to  remove  all  the  cream  by 
this  means. 

If  the  conditions  are  such  that  cool  water  can  be  constantly 
circulated  around  the  pans  containing  the  milk,  the  tempera- 
ture can  easily  be  made  to  go  below  60°  F.,  and  the  creaming 
process  is  facilitated.  When  such  conditions  are  present,  the 
depth  of  the  milk  in  the  pans  can  safely  be  increased  to  about 
6  inches.  Under  the  most  favorable  conditions  about  .5% 
fat  will  remain  in  the  skimmed  milk. 

Deep-setting  System.— This  system  is  undoubtedly  the  best 
method  of  gravity  creaming  When  properly  carried  on  the 
fat  can  be  removed  so  completely  that 
no  more  than  .2%  of  fat  remains  in 
the  skimmed  milk.  It  consists  of  put- 
ting milk  into  deep  cans  (ordinary  four- 
gallon  shotgun  cans  are  usually  em- 
ployed) immediately  after  the  milk 
has  been  drawn  from  the  cow.  Then 
it  is  put  into  cold  water,  and  generally 
cooled  down  to,  and  maintained  at,  a 

FIG.  69.— Cooley  creamer    temperature    of    about    55°    F.      The 
and  elevator. 

cream  will    rise    in    about  twenty-four 

hours.  Better  results  can  be  obtained  if  the  water  is  cooled 
down  to  about  40°  with  the  use  of  ice-water. 

One  reason  why  this  system  is  in  use  so  much,  even  in 
creamery  localities  is  that  the  cream  obtained  is  nearly  always 
of  a  good  quality.  The  farmer  knows  that  unless  the  milk 
be  cooled  quickly,  and  maintained  at  a  low  temperature,  the 
cream  will  not  rise  freely.  For  this  reason  the  milk  is  syste- 
matically and  thoroughly  cooled,  which  is  one  of  the  great 
essentials  in  order  to  check  the  growth  of  the  ferments  in  milk 


SEPARATION  OF  CREAM.  125 

and  keep  the  milk  in  good  condition.  In  many  parts  of  the 
eastern  United  States,  the  deep-setting  system  is  in  general 
use.  A  special  form  of  can  is  used.  The  can  is  simply  an 
ordinary  four-gallon  can,  about  8  inches  in  diameter  and  20 
inches  deep.  It  has  a  glass  on  one  side  near  the  bottom  or  near 
the  top,%  which  allows  the  reading  of  the  thickness  of  the  layer 
of  cream.  On  each  side  of  the  glass  is  a  graduated  scale,  which 
gives  the  reading  in  inches.  In  case  the  cream  is  being  sold 
to  a  creamery,  the  hauler  comes  along,  notes  the  depth  of  the 
layer  of  cream,  and  records  the  number  of  inches  of  cream 
opposite  the  patron's  name.  At  the  end  of  the  month,  or 
whenever  the  time  for  payment  comes,  the  money  is  appor- 
tioned according  to  the  number  of  inches  of  cream  delivered 
by  each  of  the  patrons.  No  test  for  fat  is  made.  This  is  what 
is  known  as  the  "Cooley  system,"  and  is  used  quite  extensively 
in  the  East,  especially  in  Massachusetts. 

While  cream  usually  arrives  at  the  creamery  in  a  fair  con- 
dition, there  is  the  objection  that  the  cream  is  always  thin.  It 
seldom  contains  any  more  than  18  or  20%  of  fat. 

No  good  explanation  has  yet  been  given  why  cream  in  a 
deep  layer  of  milk  at  40°  F.  should  rise  more  quickly  and  more 
completely  than  in  a  thin  layer  at  a  higher  temperature. 
*  Arnold  seeks  to  explain  it  by  saying:  "Water  is  a  better 
conductor  of  heat  than  fat;  hence  when  the  temperature  of 
the  milk  varies  either  up  or  down,  the  water  in  the  milk  feels 
the  effect  of  the  hjgat  or  cold  sooner  than  the  fat  in  the  cream 
does.  Therefore  the  cream  is  always  a  little  behind  the  water 
in  swelling  with  heat  or  shrinking  with  cold,  thus  diminishing 
the  difference  between  the  specific  gravity  of  the  milk  and 
cream  when  the  temperature  is  rising,  and  increasing  it  when 
the  temperature  is  falling." 

This  explanation  is,  according  to  Babcock,t  not  satisfactory. 
He  says:  "  Though  it  is  true  that  water  is  a  better  conductor 
of  heat  than  fat,  the  small  size  of  the  fat-globules  renders  it 

*  American  Dairying,  p.  210. 

I  Wisconsin  Experiment  Station,  Bull.  18,  p.  24. 


126  BUTTER-MAKING. 


impossible  that  under  any  circumstances  there  can  be  more 
than  a  small  fraction  of  a  degree  of  difference  between  the 
temperature  of  the  fat  and  that  of  the  milk  serum.  More- 
over, with  the  limits  of  temperature  practical  for  a  creamery, 
(90°  to  40°  F.),  the  coefficient  of  expansion  of  butter-fat  is 
more  than  three  times  -as  great  as  that  of  water,  so  that  in 
order  to  maintain  the  same  relative  differen<^  in  their  specific 
gravities  when  the  temperature  is  falling,  the  milk  serum  must 
cool  nearly  three  times  as  quickly  as  the  fat.  In  other  words, 
when  the  milk  serum  has  cooled  from  90°  to  40°,  or  50°  F., 
the  fat-glabules  should  have  lost  less  than  17°,  and  should 
still  have  a  temperature  of  over  70°  F.,  a  difference  between 
the  temperature  of  milk  serum  and  fat  of  more  than  33°.  Such 
a  condition  is  manifestly  impossible,  but  no  less  difference 
than  this  would  cause  the  fat  to  become  relatively  heavier 
than  at  first,  and  would  operate  against  the  creaming." 

A  low  temperature  increases  the  viscosity  of  the  milk, 
and  consequently  it  would  seem  that  the  resistant  force  of 
the  fat-globules  in  their  upward  passage  through  the  milk 
serum  would  be  increased,  and  thus  retard  the  creaming. 
Babcock  maintains  that  fibrin  is  partially  precipitated  when 
milk  is  allowed  to  stand  at  a  medium  high  temperature.  The 
fibrin,  when  precipitated,  forms  a  fine  network  of  threads 
permeating  the  milk  in  all  directions,  similar  to  the  network 
of  fibrin  in  coagulated  blood.  It  is  possible  to  co'nceive  that 
such  a  network  would  interfere  with  the  rising  of  the  fat-glob- 
ules, at  comparatively  high  temperatures.  The  reason  that 
fat-globules  will  ri^e  more  quickly  and  more  completely  in  the 
deep-setting  system  than  in  the  shallow-pan  system,  might 
be  explained  on  this  fibrin  theory  \vere  it  not  for  the  fact  that 
experiments  conducted  at  the  Cornell  Experiment  Station 
show  that  the  setting  and  cooling  of  milk  may  be  delayed 
long  enough  for  this  fibrin  to  form,  without  any  effect  upon 
the  separation  when  set  and  cooled. 

Probable  Explanation.  —  It  is  a  well  known  fact  in  physics 
that  most  liquids,  when  present  in  the  form  of  drops,  increase 


SEPARATION  OF  CREAM.  127 

their  surface  tensiorkjvhen  the  temperature  is  lowered.  Owing 
to  this  increase  in  surface  tension,  the  liquid  drops  unite  together 
at  a  low  temperature  much  more  f&pidly  than  they  do  at  a 
high  temperature.  For  instance,  two  drops  of  molten  iron 
unite  much  more  readily  just  previous  to  solidifying  than 
they  do  while  the  temperature  is  higher,  and  the  liquid  more 
fluid.  As  the  fat  in  milk  is  present  in  the  form  of  small  liquid 
globules,  as  mentioned  previously,  it  .geems  probable  that 
these  fat-globules  might  have  properties  similar  to  those  of 
the  liquid  mentioned  above,  and  behave  similarly  in  the  milk, 
when  set  at  low  temperatures,  .  in  accordance  with  the  deep 
setting  method.  If  the  fat-glofHiles  actVin  accordance  with 
this  theory,  it  seems  probable  that-  there  is  no  real  membrane, 
other  than  that  resulting  from  surface ,  tension,  enveloping 
each  fat-globule.  If  there  were  such  a  membrane,  composed 
of  albuminoid  chiefly,  then  undoubtedly  the  fat-globules  would 
not  assume  this  property. 

With  such  a  deep  layer  of  milk  the  lower  most  fat-globules 
must  evidently  encounter  a  great  many  other  globules  as 
they  rise.  If  the  physical  force  mentioned  does  not  facilitate 
the  process  of  uniting  the  globules,  they  would  partly  unite 
without  it.  The  more  they  unite  in  small  bunches,  or  masses, 
the  greater  would  be  the  tendency  for  them  to  rise,  as  explained 
previously,  and  more  of  the  smaller  fat-globules  would  be 
carried  along.  The  bottom  globules  would  tend  to  partly 
unite  and  form  a  filter,  which  passes  up  through  the  milk 
by  the  buoyant  force,  or  force  of  levity. 

If  this  latter  explanation  holds  true,  th^a  more  of  the  milk 
constituents  would  be  present  in  the  cream  from  the  deep- 
setting  system  than  in  the  cream  from  the  shallow-pan  system. 
By  comparing  the  cream  raised  by  the  shallow-pan  system 
with  that  raised  by  the  deep-setting  system,  before  the  cream 
has  been  removed  from  the  milk,  it  will  be  noticed  that  the 
cream  raised  by  the  shallow-pan  system  appears  to  be  much 
yellower  than  is  that  raised  by  the  deep-setting  system.  This 
'condition  can  only  be  due  to  the  fact  that  the  surface  cream, 


128 


BUTTER-MAKING. 


raised  by  the  shallow-pan  system,  contains  more  pure  fat. 
The  fat,  as  it  rises,  does  not  have  the  same  opportunity  of 
uniting  with  so  many  other  globules,  owing  to  the  comparatively 
shallow  layer  it  has  to  pass  through,  and  the  temperature  is 
not  low  enough  to  facilitate  the  uniting  of  the  globules;  that 
is,  providing  the  fat-globules  act  the  same  as  most  other  liquids 
at  lower  temperatures. 

Water-dilution  Cream  (Hydraulic). — When  milk  is  diluted 
with  water,  the  fat  or  cream  rises  much  more  rapidly  and 
completely  to  the  surface  than  it  would  in  its  undiluted  form. 
A  creaming-can  is  based  upon  this  principle,  and  it  was  expected 
to  combine  quickness,  efficiency,  and  simplicity.  The  sepa- 
rator consists  simply  of  a  tin  can  into  which  the  milk  is  poured 
and  then  diluted  with  cold  water.  In  a  few  hours  the  cream 
rises  to  the  surface.  Arrangements  are  usually  made  so  that 
the  skim-milk  can  be  drawn  off  from  the  bottom  of  the  can. 
While  the  diluted  form  of  the  milk  apparently  causes  the 
creaming  to  be  more  efficiently  and  quickly  done,  it  can  readily 
be  seen  that  in  order  to  have  a  skimming  efficiency  equal 
other  methods  of  skimming,  it  must  leave  only  about  half  as 
much  fat,  because  the  milk  is  diluted^  with  about  an  equal 
volume  of  water.  If  the  water-diluted  skimmed  milk  contains 
.2%  fat,  then  the  same  skim-milk  in  the  undiluted  form  would 
contain  .4  per  cent  fat. 

The  water-dilution  method  of  skimming  practically  spoils 
skimmed  milk  for  feeding  purposes.  Skimmed  milk  which 
contains  a  fourth  or  a  half  of  water,  has  been  robbed  of  its 
essential  relish  to  the  calf,  and  it  becomes  necessary  for  the 
calf  to  consume  too  much  volume  in  order  to  get  the  required 
amount  of  nourishment. 

This  water-dilution  system  also  gives  more  volume  to 
handle.  If  farm  dairying  were  conducted  on  a  large  scale, 
the  method  would  not  be  practicable. 

Another  objection  is  that  the  cream  which  results  from 
this  dilution  method  is  seldom  of  good  quality.  Most  well- 
water  contains  a  multitude  of  micro-organisms  which,  when 


SEPARATION  OF  CREAM.  129 

added  to  the  milk,  produce  putrefactive  and  undesirable  results. 
Much  well-water  also  is  tainted  to  a  greater  or  lesser  degree. 
Especially  is  this  so  with  water  from  shallow  wells.  Butter 
made  from  cream  which  has  been  diluted  with  water  usually 
has  a  flattish  poor  flavor. 

The  efficiency  of  separation  of  diluted  and  undiluted  milk 
is  reported  by  Wing  *  to  be  as  follows : 

Diluted  with  25%  warm  water  set  at  60°  F.  (39  trials),  0.77% 
fat  in  skim-milk; 

Undiluted,  set  at  60°  F (30  trials),  1.00%  fat  in  skim- milk 

Undiluted,  set  at  40°  F (26  trials),  0.29%    "  " 

CENTRIFUGAL  CREAMING. 

In  the  separation  of  cream  by  centrifugal  machines,  the 
same  principle  is  used  as  in  the  gravity  system  of  separation. 
The  only  difference  is  that  in  the  centrifugal  method  the  force 
which  separates  the  cream  from  the  milk  is  generated  by 
artificial  methods,  and  acts  in  a  horizontal  direction;  in  the 
gravity  system  the  force  which  separates  the  cream  from  the 
milk  is  only  that  which  results  from  the  difference  in  the  specific 
gravity  of  the  cream  and  the  skimmed  milk,  and  the  force 
acts  in  a  vertical  direction.  The  force  generated  in  the  sepa- 
rator is  several  hundred  times  greater  than  the  natural  force 
in  the  gravity  method.  For  this  reason  the  cream  separates 
almost  instantaneously  after  the  milk  has  entered  the  separator 
and  is  exposed  to  the  centrifugal  force. 

Advantages. — The  centrifugal  separator  has  several  advan- 
tages over  the  gravity  method,  which  are  apparent  without 
detailed  elaboration.  In  the  first  place,  the  range  of  tem- 
aerature  and  condition  of  the  milk  at  which  the  cream  can  be 
successfully  separated  is  much  greater  than  that  for  successful 
separation  by  the  gravity  method.  Second,  a  much  better 
quality  of  cream  can  be  obtained  by  the  centrifugal  system, 


*  Milk  and  Its  Products,  p.  105. 


130  BUTTER-MAKING. 

as  the  separation  can  be  done  before  the  milk  gets  old,  while 
by  the  gravity  method  the  time  required  for  efficient  separation 
is  so  long  that  the  cream  deteriorates  more  or  less  before  it  is 
removed  from  the  milk.  Third,  by  the  centrifugal  method  the 
thickness  of  the  cream  can  be  regulated  to  suit  requirements, 
while  by  the  gravity  method  the  thickest  cream  that  can  be 
obtained  is  about  20%.  Fourth,  by  the  centrifugal  method 
many  impurities  and  undesirable  germs  are  removed,  while  in 
the  gravity  method  the  exposure  to  open  air  more  or  less 
impure  is  likely  to  contaminate  the  milk  with  taints,  and  also 
allows  the  germs  to  fall  into  it.  Fifth,  by  the  centrifugal  method 
the  skimmed  milk  is  left  in  an  unadulterated  condition.  The 
milk  can  be  skimmed  soon  after  milking,  or  after  it  has  been 
delivered  to  the  creamery,  and  thus  be  in  the  best  possible 
condition  for  feeding  purposes.  Sixth,  the  centrifugal  method 
permits  of  a  more  thorough  separation  of  the  fat.  Butter-fat, 
as  a  rule,  is  too  expensive  to  feed,  when  good  and  much  cheaper 
substitutes  can  be  had. 

History  of  Centrifugal  Separators. — The  first  centrifugal 
separator  was  a  very  simple  one.  It  consisted  of  buckets 
hanging  on  the  ends  of  arms,  or  on  the  periphery  of  a  rotating 
horizontal  flat  wheel  which  swung  on  a  central  axis.  The  milk 
was  placed  in  the  buckets  and  whirled  for  a  time,  and  then 
the  machine  (if  we  may  call  it  such)  was  stopped,  and  the 
cream  removed  in  the  same  way  as  in  the  gravity  system. 
This  method  of  separation,  according  to  J.  H.  Monrad,*  had. 
its  origin  in  1864.  As  early  as  1859  Professor  Fuchs  of  Carls- 
ruhe,  Germany,  suggested  testing  the  richness  of  milk  by  swing- 
ing tubes  holding  the  samples  of  milk.  In  1864  Prandtl,  a 
brewer  of  Munich,  separated  milk  by  such  a  device.  In  1870 
Rev.  F.  H.  Bond,  of  Northport,  Massachusetts,  worked  out  a 
method  of  separation  which  consisted  of  two  small  glass  jars 
attached  to  a  spindle  making  200  revolutions  per  minute.  By 
one  hour's  whirling  the  cream  came  to  the  top. 

*  Dairy  Messenger,  Oct.,  1892,  p.  109. 


SEPARATION  OF  CREAM. 


131 


In  1875  Prandtl  exhibited  at  Frankfort-on-the-Main  a  con- 
tinuous separator,  which  did  not  at  the  time  attract  much 
attention,  due  chiefly  to  the  excessive  amount  of  power  needed 
to  overcome  the  resistant  force  of  the  air.  In  1876  a  Danish 
engineer  named  Winstrup  succeeded  in  improving  the  old 
bucket  method.  In  1877  Lefeldt  and  Lentch  offered  for  sale 
four  continuous  separators  with  different  capacities  (from  110 
to  600  pounds  of  milk  per  hour).  During  that  year  also  the 
first  practical  centrifugal  creamery  was  established  at  Kiel, 
Germany.  In  1877  Houston  and  Thompson  of  Philadelphia 
filed  a  patent  for  the  continuous  method  of  separation  of  cream 


FIG.  70. — First  centrifugal  separator.     (From  Dairy  Messenger.) 

from  milk.  The  patent  was  allowed  in  1891.  In  March,  1877, 
Lefeldt  and  Lentch  invented  a  separator  similar  in  construction 
to  the  hollow  bowl — a  more  recent  type.  This  machine  did  not 
revolve  at  so  rapid  a  rate  as  our  modern  machines  do,  nor 
did  it  have  arrangements  for  continuous  inflow  and  discharge. 
It  was  intermittent  in  its  work,  and  it  was  necessary  to  stop 
at  intervals  to  remove  the  cream  and  skimmed  milk.  1879 
was  the  year  which  marked  the  greatest  advancement  toward 
the  perfection  of  modern  separators.  The  appearance  of  the 
Danish  Weston,  invented  in  Denmark,  and  the  De  Laval,  in- 
vented in  Sweden  during  that  year,  marked  a  great  advance- 


132  BUTTER-MAKING. 

ment  in  the  separation  of  cream  from  milk.  This  led  to  con- 
tinuous milk  and  cream  discharges,  and  consequently  also  to 
the  continuous  inflow  of  whole  milk.  These  machines  were 
of  the  hollow-bowl  construction. 

Modern  Separators. — Since  the  year  when  the  Danish  Weston 
and  the  De  Laval  machines  were  invented,  many  different 
types  of  separators  with  different  contrivances  within  the  bowl 
have  been  put  upon  the  market.  Baron  Bechtelsheim,  of 
Munich,  is  given  the  credit  of  having  discovered  that  certain 


FIG.  71. — The  United  States  separator. 

contrivances  on  the  inside  of  the  machine  increase  the  efficiency 
and  capacity  of  skimming.  This  discovery  was  made,  accord- 
ing to  J.  H.  Monrad,*  in  1890.  This  invention  was  bought  by 
the  De  Laval  Company. 

The  principal  part  of  practically  all  the  separators  is  a  bowl 
rotating  in  a  vertical  position,  with  or  without  contrivances 
inside  the  bowl.  Machines  having  a  bowl  rotating  in  a  hori- 
zontal position  are,  so  far  as  the  authors  know,  not  in  use  at 
the  present  time.  Such  a  machine  was  once  manufactured  at 
Hamburg,  Germany,  and  was  called  "Peterson's  Centrifugal 


*  Dairy  Messenger,  Jan.  1892,  p.  9. 


SEPARATION  OF  CREAM. 


133 


Machine."    Another  German  machine,  called  "The  Page,"  was 
also  manufactured  in  the  horizontal  bowl  style. 

From  the  above  it  will  be  noticed  that  four  separate  steps 
are  recognizable  in  the  evolution  and  improvement  of  separators : 

1.  Revolving  Bucket  Centrifuge; 

2.  Intermittent  Hollow  Bowl; 

3.  Continuous  Hollow  Bowl; 

4.  Continuous  Separator  with  contrivances  within  the 

Bowl. 


FIG.  72. — The  Simplex  separator. 

The  science  and  practice  of  separation  of  milk  and  cream 
have  seemingly  reached  a  high  state  of  efficiency.  It  seems 
almost  improbable,  considering  the  many  new  improved  sepa- 
rators on  the  market  that  any  other  great  improvement  could 
be  made  which  would  add  a  separate  stage  to  the  improve- 
ment of  our  best  centrifugal  milk  separators  of  to-day. 

Classification  of  Separators. — Owing  to  the  many  different 
standard  types  of  separators  now  on  the  market,  it  is  impossible 
to  describe  each  one  in  detail.  For  this  reason  the  classifi- 


134 


BUTTER-MAKING. 


cation  appearing  below  has  been  made.  There  are  undoubtedly 
many  other  types,  especially  in  foreign  countries,  with  which 
the  writers  are  not  familiar,  and  which  are  not  mentioned  here. 
The  following  classification  will,  in  some  measure,  illustrate 
the  different  makes  of  separators  on  the  market  to-day: 


f  Omega:- 

Cause    milk    to     Empire.             ., 

Farm  sep- 

pass     in     thin  J  Davis, 
sheets  vertical-  |  United  States. 

arators. 

ly  in  bowl. 

National  . 

.  Reid. 

Contrivances 
in  bowl. 

Cause    milk    to 

r  Dairy  Qusen. 
Da  Laval. 
Peerless. 

separate      into 

Swea. 

almost   h  o  r  i  -  • 

Westphalia 

Se  para- 
tors. 

zontal         thin 
sheets. 

(Cleveland)  . 
Iowa. 

Internat.  Cream 

. 

•    Harvester. 

f  Improved  Danish  Weston  (Reid). 
r  Hollow  bowl        \  Sharpies  (old  style). 

[  De  Laval  (old  style). 

Creamery 

Cause    milk    to  " 

»  United  States. 

power 
separa- 
k    tors. 

Contrivances  in  , 

pass    in     thyj 
sheets      verti- 
cally in  bowl. 

Simplex. 
Sharpies  (new 

style). 

-    bowl-                   1  Cause    milk    to  1 

separate  in  al-  I  De  Laval. 
i    most    horizon-  f  Springer. 
[    tal  sheets.          j 

Many  of  these  separators  which  cause  the  milk  to  pass 
up  and  down  in  vertical  sheets  have  the  bowl  contrivances 
corrugated,  and  perforated  with  holes  so  that  the  skim-milk 
and  cream  assume  also  a  partly  horizontal  direction. 

Process  of  Separation. — From  the  illustrations,  the  structure 
of  the  more  common  types  of  separator  bowls  is  readily 
understood.  The  whole  milk  may  be  made  to  enter  at  the 
bottom  or  top  o!  the  bowl  when  revolving.  In  the  Sharpies, 
the  milk  enters  at  the  bottom.  The  more  common  way 
is  to  have  the  whole  milk  enter  at  the  top.  As  the 
milk  enters  the  bowl  and  is  exposed  to  the  centrifugal  force, 


SEPARATION  OF  CREAM. 


135 


it  immediately  begins  to  separate  into  three  distinct  layers. 
The  centrifugal  force  acting  in  a  horizontal  direction  forces 
the  heaviest  portions  of  the  milk  and  the  precipitated  albu- 
minoids, ash,  filth,  and  a  multitude  of  germs  over  next  to 


FIG.  73. — The  Reid  separator. 


FIG.  74. — The  Sharpies  separator. 


the  wall  of  the  separator  bowl,  and  into  a  solid  and  more  or 
less  gelatinous  layer,  which  is  known  as  the  "  separator  slime." 
In  very  impure  milk  this  substance  is  so  plentiful  that  it  is 
likely  to  clog  the  separator  in  a  very  short  time,  and  before 
much  separation  is  accomplished  it  is  necessary  to  clean  out 
the  bowl.  The  second  layer  is  the  skim-milk,  while  the  cream, 
being  the  lightest,  is  forced  to  the  center  of  the  bowl  and  forms 
the  third  portion  mentioned.  There  is  no  distinct  line  of 
demarcation  between  the  layers  of  skimmed  milk  and  cream. 
They  overlap  each  other  and  form  a  sort  of  zone,  rather  than 
a  sharp  separation.  The  richest  cream  is  nearest  the  center 
of  the  bowl,  and  gets  thinner,  toward  the  outer  portion  of  the 
bowl;  consequently,  by  turning  the  outlet  for  the  cream,  or 
cream-screw,  nearer  the  center  of  the  bowl,  the  cream  is  increased 


136  BUTTER-MAKING. 

in  richness.  Turning  it  away  from  the  center  causes  the  cream 
to  be  thinner.  The  skimmed  milk  that  is  forced  clear  to  the 
circumference  of  the  bowl  contains  the  least  fat,  and  con- 
sequently the  skimmed  milk  is  always  first  removed  from  this 
portion  of  the  bowl.  Usually  the  skim  milk  outlet  is  brought 
in  towards  the  center  of  the  bowl  at  one  end  through  tubes 
extending  from  the  circumference  of  the  bowl.  If  this  were 
not  done,  some  difficulty  would  be  involved  in  arranging  a 


FIG.  75. — Showing  "butter  extractor"  FIG.    76. — Showing  cross-section  of 
attached  to  De  Laval  separator.    The  De  Laval  separator  bowl, 

butter  extractor  is  not  known  to  be 
in  use  now. 

receiving-pan  for  the  discharged  skim-milk.  If  the  skim- 
milk  were  discharged  near  the  circumference  of  the  bowl,  it 
would  come  out  with  a  heavy  force.  Also,  if  the  outlet  for  the 
skimmed  milk  were  near  the  circumference  of  the  bowl,  a 
great  deal  more  power  would  be  required  to  run  the  machine. 
As  the  skimmed  milk  passes  through  the  tubes  towards  the 
center  it  gives  up  its  force.  The  nearer  the  skimmed-milk 
outlet  can  be  brought  to  the  center  of  the  bowl,  the  easier 
will  the  machine  run. 


SEPARATION  OF,  ORE  AM.  137 

The  size  of  the  skimmed-milk  outlet  is  usually  made  so 
that  it  bears  a  certain  relation  to  the  size  of  inlet,  size  of  bowl, 
and  to  the  speed  of  the  machine.  Most  skimmed-milk  outlets 
are  made  so  as  to  discharge  from  .4  to  about  .9  or  a  little  more, 
of  the  whole  milk  that  enters  the  bowl.  The  remainder  is 
the  cream,  which  is  forced  to  the  center  of  the  bowl  and  dis- 
charged through  the  cream  outlet. 

RELATIVE    AMOUNT    AND    RICHNESS    OF    MILK    AND   CREAM 

OBTAINED. 

The  conditions  which  affect  the  relative  amount  of  cream 
may  be  said  to  be  as  follows: 

1.  Regulation  of  the  cream  or  skimmed-milk  screw. 

2.  Rate  of  inflow  to  the  bowl. 

3.  Speed  of  the  machine. 

4.  Temperature  of  the  milk. 

i.  Regulation  of  the  Cream  or  Skimmed-milk  Screw. — All 
modern  machines,  so  far  as  known,  have  a  device  by  which 
the  relative 'amount  of  skimmed  milk  and  cream  can  be  con- 
trolled, and  consequently  the  richness  of  the  cream.  Some 
machines  have  this  device  in  the  form  of  a  cream- screw,  and 
others  as  a  skim-milk  screw.  The  cream-screw  in  most  of 
the  machines  has  a  hole  on  one  side  of  it  through  which  the 
cream  is  discharged.  If  this  screw  is  turned  so  as  to  make 
the  hole  nearer  the  center,  then  the  cream  will  be  richer  and 
less  in  quantity.  If  turned  away  from  the  center,  then  more 
and  thinner  cream  will  be  discharged.  In  some  machines  there 
is  a  skim-milk  screw  which  serves  the  same  purpose.  The 
method  then  of  regulating  the  relative  amount  of  cream  and 
skimmed  milk  works  in  just  the  opposite  direction;  that  is, 
when  thicker  cream  and  less  of  it  is  wanted,  then  the  milk-screw 
is  turned  so  as  to  bring  the  skimmed-milk  outlet  nearer  the 
circumference  of  the  bowl.  This  gives  more  skimmed  milk 
$nd  consequently  less  cream.  If  thinner  and  more  cream  is 
wanted,  then  the  screw  is  turned  in.  This  causes  more  milk 
to  flow  out  through  the  cream  outlet.  The  Reid  hand  separator 


138  BUTTER-MAKING. 

is  an  example  of  this  latter  class.  These  two  methods  of  regu- 
lating the  thickness  and  amount  of  cream  are  the  most  common. 
It  cannot  be  done  while  the  machine  is  in  motion.  By  some 
this  is  considered  a  drawback. 

Other  separators  have  a  device  whereby  the  amount  of 
cream  can  be  regulated  while  the  machine  is  in  motion.  For 
instance,  on  the  improved  Danish  Weston,  there  is  a  screw 
attached  to  the  skim-milk  discharge-tube,  by  turning  which 
the  end  or  point  of  the  tube  can  be  made  to  be  closer  or  farther 
away  from  the  center,  thus  regulating  the  relative-  amount 
of  cream  and  skimmed  milk,  and  the  thickness  of  the  cream. 

2.  Rate  of  Inflow. — The  rate  of  inflow  of  milk  to  the  sepa- 
rator has  a  large  influence  on  the  relative  amount  of  cream 
and  skimmed  milk.     The  greater  the  inflow  to  the  separator, 
the  more  and  thinner  cream  will  be  obtained,  and  with  a  dimin- 
ished inflow  the  less  and  thicker  cream  is  obtained.     This  is 
due  to  the  fact  that  at  a  given  velocity  of  the  machine  the 
skim-milk    discharge    remains     practically    constant.     So,    if 
more  milk  is  turned  on,  the  only  place  where  the  discharge 
can  increase  is  through  the  cream  outlet;    and  if  the  inlet  is 
diminished,  the  cream  will  diminish  until  a  certain  time,  when 
the  amount  of  milk,  which  runs  into  the  machine,  equals  the 
amount  discharged  through  the    skim- milk   outlet,    and  then 
there  will  be  little  or    no  cream.     This    is   aptly  illustrated 
by  Wing:   "  If  the  milk  is  turned  into  the  bowl  at  such  a 
rate  that  .8  escapes  through  the  skim-milk  outlet,  we  shall 
have  .8  skim-milk  and  .2  cream.     If,  now,  we  reduce  the  rate 
of  inflow  by  .1,  we  shall  get  just  as  much  skimmed  milk  as 
before,  but  only  half  as  much  cream ;  or,  if  the  inflow  is  increased 
.1,  we  shall  get  the  same  amount  of  skimmed  milk  and  one 
and  a  half  times  as  much  cream."     The  completeness  of  sepa- 
ration will  be  the  same  so  long  as  the  separator  is  run  within 
the  range  of  its  capacity. 

3.  Speed, — The  speed  of  the  separator  influences  the  rela- 
tive amount  of  the  cream  and  skimmed  milk  only  in  so  far 
as  an  increase  in  the  speed  of  the  bowl  increases  the  capacity 


SEPARATION  OF  CREAM.  139 

of  the  skim-milk  outlet,  due  to  a  more  rapid  discharge 
through  the  skim-milk  outlet.  The  slower  the  bowl  re- 
volves the  less  skimmed  milk  will  be  discharged,  and  conse- 
quently, if  the  inlet  is  constant,  more  and  thinner  cream  will 
be  the  result.  It  should  be  stated  in  connection  with  this 
that  the  efficiency  of  skimming  depends  to  a  large  extent 
upon  the  speed,  and  if  attempts  are  made  to  increase  the  amount 
of  cream  and  decrease  the  percentage  of  fat  in  it,  by  lowering 
the  speed,  an  abnormal  amount  of  fat  will  be  left  in  the  skimmed 
milk. 

4.  Temperature. — The  temperature  of  milk  usually  does  not 
influence  the  relative  amount  of  milk  and  cream  very  much. 
The  higher  the  temperature  the  more  fluid  the  milk  becomes, 
and  consequently,  all  other  conditions  being  the  same,  slightly 
more  milk  will  run  through  at  a  high  temperature  than  is  the 
case  with  a  lower  temperature.  This  increase  will  show  itself 
chiefly  in  the  amount  of  cream,  as  the  higher  temperature 
has  a  greater  relative  effect  upon  the  cream  than  it  has  upon 
the  milk.  By  increasing  the  temperature  of  the  milk,  slightly 
more  and  thinner  cream  is  obtained. 

CONDITIONS   AFFECTING  EFFICIENCY  OF  SEPARATORS. 

i.  Manner  of  Heating  Milk. — Owing  to  the  fact  that  fat- 
globules  rapidly  change  their  shape  and  property  by  exposing 
them  to  heat  and  excessive  agitation,  it  is  essential  that  care 
should  be  taken  in  heating  milk  previous  to  skimming.  When 
fat-globules  are  heated  they  become  more  liquid,  and  if  stirred 
very  much  the  clusters  of  fat-globules  break  up  more  rapidly. 
The  individual  globules,  if  stirred  violently,  will  break  or  sub- 
divide into  several  small  ones.  The  higher  the  temperature 
of  the  milk,  the  more  fluid  the  milk  becomes,  and  the  easier 
the  separation.  If  milk  is  stirred  violently,  the  individual  fat- 
globules  break  up  into  smaller  ones,  which  are  separated  from 
milk  with  difficulty.  The  following  table  *  illustrates  what 

*  Hoard's  Dairyman,  Fort  Atkinson,  Wis. 


140 


BITTER-MAKING. 


effect  the  different  degrees  of  agitation  of  milk  has  upon  the 
efficiency  of  separation : 


'ilk  heated 
:ilk  heated 

in  vat, 
n  Paste 

not  pumped 

Av.  Fat 
No.  of  Per  Cent 
Experi-      in 
ments.    Skim- 
milk. 
10           117 

urizer  ,  200  revolutions  of  agitator  per  minute       8       .115 

' 

i 

250 

3         .118 

I 

i 

300 

8       .134 

I 

i 

350 

2       .143 

( 

« 

400 

'                     7       .198 

ilk  pun 

« 
iped  by  the 

t                  fit! 

'      with  ti 

I                   HI 

500 
•  turbine  pump  at  122°  F 

4        .225 
3         129 

"      "    64°  F 

3         119 

le  pump,  effective  at  122° 

<        "             «         "     g4° 

3         117 

3       .115 

In  the  above  experiments  the  diameter  of  the  agitator  in 
the  Pasteurizer  was  14  inches.  The  speed  at  the  periphery, 
at  250  revolutions  per  minute,  was  5  feet  per  second. 

It  will  be  seen  from  the  above  table  that  the  higher  the 
speed  of  the  agitator,  the  greater  the  difficulty  in  getting  a 
complete  separation.  Besides  the  speed  of  the  agitator  in 
the  heating  apparatus,  undoubtedly  the  shape  of  the  Pas- 
teurizer is  a  factor  in  determining  the  efficiency  of  the 
subsequent  separation.  For  instance,  the  milk  in^most  hori- 
zontal Pasteurizers  is,  even  at  low  speed,  exposed  to  con- 
siderable agitation. 

If  the  milk  is  suddenly  heated  from  a  low  temperature  to 
about  80°  or  90°  F.  and  then  skimmed,  the  heating  does  not 
facilitate  the  skimming  process  very  much.  It  is  essential 
that  the  milk  should  be  exposed  to  this  temperature  for  a 
considerable  time.  The  fat-globules  do  not  warm  as  rapidly 
as  the  milk-serum.  This  diminishes  the  difference  between  the 
specific  gravity  of  the  two  substances,  consequently  complete- 
ness of  separation  becomes  more  difficult.  If  milk  is  heated 
to  a  high  temperature,  say,  for  instance,  170°  F.,  then  the 
separation  will  be  sufficiently  complete  without  exposing  the 
milk  for  any  length  of  time  to  that  temperature. 


SEPARATION  OF  CREAM.  .     141 

Machines  are  now  made,  and  are  on  the  market,  which  will 
bring  the  milk,  or  the  fat-globules  in  the  milk,  into  such  a 
condition  that  they  cannot  be  separated  from  the  milk.  The 
process  is  called  "homogenization.'1  It  consists  of  bringing 
the  milk  under  certain  pressure,  and  then  forcing  it  out  through 
a  special  valve.  This  relief,  through  this  special  valve,  causes 
the  fat-globules  to  divide  up  into  very  minute  ones.  They 
divide  up  to  such  an  extent  that  they  cannot  be  separated 
from  the  milk  by  gravity  methods,  and  it  is  impossible  to  get 
a  complete  separation  by  centrifugal  methods.  Homogeniza- 
tion  of  milk  is  carried  on  to  some  extent  in  Europe.  The 
process  practically  insures  uniform  quality  to  the  milk  patrons 
in  the  distribution  of  milk  in  cities,  and  secures  a  more  uniform 
consistency  of  the  product. 

2.  Condition  of  the  Milk. — In  order  to  get  complete  separation, 
and  keep  the  separator  in  good  running  order,  it  is  essential 
that  the  milk  should  be  in  as  good  physical  condition  as  possible. 
Coagulated,  slimy,  or  otherwise  viscous  milk  separates  with 
difficulty.  When  such  milk  is  on  hand  it  should  not  be  mixed 
with  the  milk  that  is  in  good  condition,  as  it  might  tend  to  coag- 
ulate more  of  the  good  milk,  and  the  coagulated  or  slimy  lumps 
are  likely  to  clog  the  separator.  Such  milk  should  be  left 
until  all  the  good  milk  has  been  separated.  Then,  if  the  coagu- 
lated or  slimy  milk  is  thoroughly  stirred  so  as  to  reduce  the 
lumpiness  of  it,  it  may  be  run  through  the  separator  success- 
fully. It  is  a  good  plan  not  to  feed  the  separator  quite  so 
heavily  when  this  quality  of  milk  is  being  run  through.  By 
shutting  off  the  inlet  a  little,  it  will  usually  run  through  without 
clogging.  Milk  containing  impurities  in  suspension  should  be 
thoroughly  strained  previous  to  separation. 

Overfeeding  the  Separator. — When  a  separator  is  being 
overfed  with  milk  there  is  a  tendency  for  the  machine  to  do 
less  complete  work.  This  is  due  to  the  fact  that  the  more 
milk  is  being  fed  into  the  separator  the  less  time  it  will  be 
exposed  to  the  centrifugal  force.  It  is  iiffpossible  to  underfeed 
the  separator  as  well.  As  has  been  mentioned  before,  the 


142  BUTTER-MAKING. 

inlet  can  be  closed  to  such  an  extent  as  to  cause  nearly  all  the 
discharge  to  take  place  through  the  skim-milk  tube. 

As  a  rule  when  the  machine  has  been  set  so  as  to  allow  the 
milk  to  flow  in  at  a  certain  rate,  it  will  continue  to  admit  prac- 
tically the  same  amount  of  milk  all  through  the  skimming 
period.  Among  the  conditions  which  may  alter  the  rate  of 
inflow  to  some  extent,  are  the  amount  of  heat  and  the  change 
of  pressure,  due  to  different  amounts  of  milk  in  the  receiving- 
vat.  Temperature  will  slightly  affect  the  rate  of  inflow.  The 
higher  the  temperature,  all  other  conditions  being  the  same, 
the  more  milk  will  pass  through  the  inlet. 

3.  Speed. — All  modern  machines  have  a  device  by  which  their 
speed  can  be  determined.  Most  speed  indicators  consist  of  a 
little  wheel,  which,  when  pushed  up  against  the  spindle  of  the 
separator  while  running,  turns  around  and  permits  the  calcu- 
lation of  the  speed  of  the  separator.  If  the  wheel  on  the  speed- 
indicator  turns  10  revolutions  during  ten  seconds,  the  machine 
would  turn  1000  times  during  the  same  time.  During  one 
minute  the  separator  will  run  six  times  as  many  revolutions, 
or  6000,  as  ten  seconds  is  one-sixth  of  a  minute.  Most  speed- 
indicators  are  so  adjusted  as  to  turn  one  revolution  for  every 
100  revolutions  of  the  machine.  The  higher  the  speed,  the 
more  thorough  is  the  separation.  Nearly  all  machines  are 
balanced  to  do  the  best  work  at  a  certain  definite  speed,  varying 
with  different  machines,  and  indicated  in  the  directions  for 
operating.  It  is  essential  that  the  machine  should  be  brought 
up  to  speed  gradually,  and  no  milk  be  allowed  to  flow  through 
it  until  after  it  has  acquired  its  full  speed. 

During  the  run,  all  machines  are  likely  to  vary  more  or  less 
in  speed,  owing  to  different  causes.  Pulleys  are  likely  to  slip 
on  the  shaft,  and  belts  are  likely  to  become  loose,  and  thus 
cause  variations  in  the  speed.  The  steam  pressure  is  likely 
to  get  low,  and  cause  all  of  the  machinery  in  the  creamery  to 
run  more  slowly.  This  cause,  however,  is  not  a  very  common 
one  where  belt  separators  are  used.  If  the  engine  has  an  auto- 


SEPARATION  OF  CREAM.  143 

matic  governor  on  it,  the  speed  is  usually  quite  uniform.  Where 
steam-turbine  machines  are  used,  the  speed  of  the  machine  is 
more  likely  to  vary  with  the  different  amounts  of  steam  pressure 
on  the  boiler.  With  turbine  separators  it  is  very  essential  to 
keep  an  even  steam  pressure.  Some  turbine  separators  have 
a  safety-valve  attached  to  prevent  too  high  speed. 

The  reason  why  the  prevention  of  a  variation  in  speed  is  so 
essential  is  that  a  slight  variation  in  the  speed  has  a  compara- 
tively large  effect  upon  reducing  or  increasing  the  centrifugal 
force.  The  centrifugal  force  generated  in  a  machine  varies 
according  to  the  diameter  of  the  bowl,  and  according  to  the 
speed  of  the  machine.  The  greater  the  diameter  of  the  bowl, 
the  less  speed  of  velocity  is  required  in  order  to  get  a  certain 
force.  The  centrifugal  force  varies  in  direct  proportion  to  the 
diameter  of  the  bowl;  that  is,  if  the  diameter  of  the  bowl  be 
doubled,  then  at  the  same  speed,  the  centrifugal  force  has  been 
doubled.  The  centrifugal  force  varies  in  quadratic  proportion 
to  the  speed  of  the  machine;  that  is,  if  the  speed  of  the  sepa- 
rator is  doubled,  the  centrifugal  force  is  increased  four  times. 
From  this  it  will  be  seen  that  speed  is  a  great  factor  in  deter- 
mining the  centrifugal  force  generated.  It  is  not  a  good  plan 
to  have  the  diameter  of  the  bowl  too  large,  for  the  following 
reasons :  A  large  bowl  is  more  likely  to  be  thrown  out  of  balance; 
it  is  harder  to  keep  on  the  bearings;  and  it  is  heavier  and  more 
unhandy  to  handle.  For  these  reasons  it  is  better  to  lessen  the 
diameter  of  the  bowl  and  increase  the  speed.  This,  of  course, 
is  true  only  to  a  certain  limit. 

Steadiness  in  Running. — Smooth  running  of  a  separator  is 
one-  of  the  first  essentials.  If  a  machine  runs  roughly,  there 
will  not  be  good  separation,  and  it  is  dangerous  to  run  it.  The 
bowl  itself  is  likely  to  jump  out,  or  burst.  The  causes  for 
unsteadiness  in  running  are  many.  It  may  be  due  to  a  bent 
or  sprung  spindle;  the  machine  not  standing  level;  changing 
covers  to  bowls;  using  clamps  which  do  not  fit  the  bowl  cover; 
unclean,  worn-out  bearings;  condition  of  the  bowl,  and  con- 
trivances inside  the  bowl ;  and  dented  and  rusty  bowls.  Occa- 


144  BUTTER-MAKING. 

sionally  it  happens  that  a  machine  is  run  backwards.     This  is 
likely  to  cause  the  cover  of  the  bowl  to  run  off. 

Thickness  of  Cream. — The  efficiency  of  skimming  depends 
to  some  extent  upon  the  thickness  of  the  cream  skimmed. 
Most  separators,  however,  will  skim  within  quite  a  wide  range 
as  to  thickness.  The  richness  of  cream  usually  skimmed  by 
separators  is  about  from  25%  to  50%.  Most  separators,  how- 
ever, will  do  good  skimming  even  if  the  cream  contains  as  high 
as  60%  fat.  This,  however,  should  be  considered  to  be  about  the 
maximum,  in  order  to  get  the  best  results  from  a  separator. 

Slush  in  Bowl. — As  has  been  mentioned  before,  there  is 
always  a  thick,  slimy  substance  which  adheres  to  the  bowl- 
wall.  The  composition  of  separator-slime  is,  according  to 
Fleischmann,  as  follows: 

Water 67.3 

Fat.. 1.1 

Caseous  matter 25.9 

Other  organic  substances 2.1 

Ash.  .  3.6 


100.0 

At  the  center  of  the  bowl,  or  along  the  axis  which  runs 
perpendicular  in  the  bowl,  there  is  always  considerable  cream. 
It  is  practically  impossible  to  get  all  the  cream  out  of  the  bowl, 
even  if  it  is  flushed  with  much  water.  The  amount  of  slush 
varies  somewhat  with  the  different  kinds  of  separators.  For 
this  reason,  it  is  essential  that  it  should  be  taken  into  con- 
sideration when  the  comparative  efficiency  of  skimming  of 
different  separators  is  considered.  When  the  test  extends  over 
a  comparatively  long  period,  arid  the  milk  skimmed  amounts 
to  several  thousand  pounds,  then  the  bowl -slush  does  not  affect 
the  conditions  for  comparative  results  very  much;  but  when 
the  test  is  short,  and  only  a  hundred  pounds  of  milk,  or  a  similar 
amount,  is  skimmed,  then  the  amount  of  fat  left  in  the  bowl- 
slush  will  have  considerable  influence  upon  deciding  which  one 
is  the  most  efficient  machine. 


SEPARATION  OF  CREAM.  145 

General  Remarks.— In  order  to  keep  the  separator  in  good 
running  order,  it  must  receive  care.  The  belt  should  not  be 
too  tight,  nor  too  loose.  If  too  tight  it  is  likely  to  bind,  heat, 
and  set  the  bearings  of  the  separator.  If  too  loose  it  is  likely 
to  slip,  and  to  wear  out  more  quickly.  The  machine  should  be 
well  oiled.  It  is  better  to  use  a  trifle  too  much  oil  than  not 
enough.-  If  a  bearing  is  once  heated,  the  machine  will  never 
run  as  well  again. 

The  bowl  should  be  handled  with  great  care.  Bowls,  or 
parts  belonging  to  the  bowl,  can  be  kept  from  rusting  by  boiling 
them  in  water,  or  by  steaming  them  thoroughly  after  they 
have  been  cleaned.  If  scalding-hot  water  is  used  before  the 
milky  portion  has  been  washed  off,  the  albuminoids  will  be 
scalded  on  to  such  a  degree  that  it  is  difficult  to  get  them  off. 
This  applies  to  all  dairy  and  creamery  utensils.  Hot  water 
is  said  to  be  best  in  which  to  dip  tin  or  iron-ware  after  washing 
in  order  to  keep  them  from  rusting.  If  the  bowl,  pail,  or 
whatever  utensil  it  may  be,  is  turned  over  to  drain  after  being 
dipped  in  hot  water,  the  heat  taken  up  by  the  utensil  will  in  a 
short  time  perfectly  dry  the  apparatus.  If  the  bowl  is  steamed, 
it  should  be  heated  thoroughly  to  make  it  dry  quickly. 

If  the  milk  supply  gets  short  during  the  run,  and  it  is  neces- 
sary to  run  the  machine  without  feeding  milk,  then  the  machine 
should  always  be  flushed  with  luke-warm  water.  This  will,  in 
a  measure,  prevent  clogging.  Scalding-hot  water  should  never 
be  used  for  flushing  the  separator.  The  cream  and  skimmed- 
milk  tubes  should  be  carefully  cleaned,  with  the  special  wire 
provided  for  that  purpose,  each  time  the  machine  is  washed. 
The  contrivances  on  the  inside  of  the  bowl  should  also  be 
handled  with  care  so  as  not  to  injure  them  in  any  way.  They 
should  be  treated  with  hot  water,  as  mentioned  above,  in  order 
to  keep  them  from  rusting. 

When  the  bowl  is  not  to  be  used  for  some  time,  it  should 
be  oiled  well  so  as  to  prevent  it  from  rusting.  It  is  easier  to 
oil  a  separator  bowl  than  it  is  to  scour  the  rust  off  later  on. 


CHAPTER  XII. 

FARM  SEPARATORS. 

THE  conditions  affecting  the  efficiency  of  skimming  and 
the  relative  amount  of  cream  and  skim-milk  described  under 
"  Creamery  Separation  "  apply  to  farm  separators  as  well.  The 
conditions  under  which  the  farm  separators  are  operated  war- 
rant a  few  separate  remarks  on  this  subject. 

Introduction  of  Farm  Separators. — Small,  or  hand,  separa- 
tors, have  been  manufactured  for  a  good  many  years.  It  is, 
however,  not  until  comparatively  recent  years  that  they  have 
been  numerous  enough  to  be  of  commercial  importance.  The 
people  in  the  Central  West  (Iowa,  Kansas,  Nebraska,  Missouri, 
Minnesota,  and  Illinois)  have  been  most  prominent  in  intro- 
ducing farm  separators.  In  the  'year  1894  hand  separators 
were  introduced  in  Iowa,  but  it  was  not  until  1898  that  they 
gained  sufficient  foothold  to  be  of  commercial  importance. 
According  to  the  Iowa  Dairy  Commissioner's  report  of  1898, 
there  were  then  only  904  farm  separators  in  the  state  of  Iowa. 
Now,  in  1904,  there  are  more  than  17,000  separators.  Glancing 
over  the  statistics  it  will  be  seen  that  the  rate  of  increase  in 
hand  separators  during  the  years  intervening  between  1898 
and  1904  has  been  uniform  and  rapid.  This  proves  that  the 
dairy  business  is  still  in  a  transitional  period,  and  the  intro- 
duction of  hand  separators  still  on  the  increase.  Such  a  time 
in  any  industry  is  always  accompanied  by  more  or  less  incon- 
venience, difficulty,  and  dissatisfaction.  To  receive  a  part  of 
the  :butter-fat  in  the  form  of  cream,  and  the  other  part  in  the 
form  of  milk,  is  undesirable.  Under  such  a  system  it  is  always 
difficult  to  get  milk  or  cream  routes  organized;  proper  sampling 

146 


FARM  SEPARATORS. 


147 


becomes  more  or  less  difficult,  and    the    quality  of  butter  is 
harder  to  control. 

Reasons  for  Introducing  Farm  Separators. — It  requires  an 
investment    of    about    $100  to  purchase    a    hand    separator. 


FIG.  77. — The  Omega  hand  separator. 

Most  of  the  butter  made  from  hand-separator  cream  is  of  poor 
quality.  Still,  in  the  face  of  this,  separators  have  rapidly  -iu 
creased.  It  may  be  concluded  that  there  must  be  some  good 
reasons  why  farmers  are  continuing  to  invest  in  farm  separators. 
There  are  undoubtedly  many  reasons  why  farmers  prefer  hand 


148  BUTTER-MAKING. 

separators;  reasons  which  are,  to  a  large  extent,  confined  to 
local  conditions.  Only  a  few  of  the  chief  and  general  reasons  can 
be  given  here : 

(1)  The  farmer  is  able  to  skim  the  milk  at  once  after  it 
has  been  drawn,  thereby  enabling  him  to  feed  the  milk  while 


FIG.  78. — The  Iowa  hand  separator.    FIG.  79. — The  De  Laval  hand  separator 

(Baby  Xo.  1). 

it  is  in  a  warm,  sweet,  unadulterated  condition.  If  he  hauled 
the  milk  to  the  creamery,  the  skimmed  milk  would  be  likely 
to  come  back  in  a  sour  and  curdled  condition,  and  at  times 
watery.  (In  a  well-conducted  creamery  these  latter  conditions 
do  not  exist.) 

(2)  The  high  cost  of  hauling  in  many  instances  makes  it 
almost  impossible  to  get  the  milk  to  the  creamery.  Even  if 
the  roads  are  good,  the  distance  to  the  creamery  is  frequently 
so  great  that  it  is  impossible  to  get  haulers,  nor  is  it  practical 
for  every  farmer  to  haul  his  own  milk  every  day.  Especially 
is  this  so  during  the  busy  season  of  the  year.  In  the  fall, 
when  milk  is  scarce,  it  is  almost  impossible  for  the  hauler  to 


FA  RM  SEP  A  RA  TORS. 


149 


get  enough  milk  to  make  it  profitable.     In  many  cases  it  is 
necessary  to  pay  an  excessive  price  for  hauling  milk. 

When  cream  routes  are  established  instead  of  milk  routes, 
one  hauler  can  usually  cover  as  much  territory  as  three  could 


Fia.  80. — Simplex  hand  separator  and  the  different  parts  of  bowl. 

under  the  milk  system.  Two  thousand  pounds  of  milk,  testing 
4%  and  containing  80  pounds  of  fat,  would  represent  approx- 
imately a  load  of  milk.  At  12  cents  per  100  pounds,  this 
would  mean  a  cost  of  $2.40  for  getting  that  much  milk 


150 


BUTTER-MAKING. 


hauled.  If  the  same  amount  of  butter -fat  were  hauled  in,  the 
form  of  cream,  it  could  be  gathered  for  about  1£  cents  per 
pound  of  fat,  or  the  cost  of  hauling  in  this  particular  case 
would  be  $1.20.  Under  the  milk  system  it  would  be  neces- 
sary to  haul  the  milk  to  the  creamery  every  day,  while 
under  the  cream  system  it  is  usually  gathered  every  other 
day  in  the  summer,  and  every  three  days  in  the  winter.  It 
is  usually  considered  that  there  is  a  saving  of  about  1^  to  2 


FIG.  81. — Sharpies  separator  and  parts  of  bowl. 

cents  per  pound  of  butter-fat  in  hauling,  by  making  use  of  the 
cream  system  instead  of  the  milk  system.  This,  of  course, 
would  vary  according  to  local  conditions, 

3.  The  use  of  hand-separators  makes  farmers  more  inde- 
pendent than  they  are  under  the  whole-milk  system.  They 
are  not  compelled  to  support  their  local  creamery  unless  they 
deem  it  advisable.  They  can  ship  their  cream  to  any  place  that 
they  may  choose.  If  the  butter  from  the  hand-separator  cream 
is  going  to  be  of  as  good  quality  as  that  made  by  the  whole- 
milk  system,  the  cream  should  be  delivered  as  often  as  possible. 
Every  day  is  preferable  to  every  other  day.  In  case  frequent 


FARM  SEPARATORS. 


151 


delivery  is  made,  then  it  becomes  quite  essential  for  the  farmer 
to  patronize  the  local  creamery,  as  very  few  farmers  keep  suffi- 
cient cows  to  get  enough  cream  to  pay  them  to  ship  by  rail 


FIG.  82. — The  National  hand  separator  and  parts  of  bowl. 

every  day.  Usually  it  does  not  cost  much  more  to  ship  a 
can  full  of  cream  than  it  does  to  ship  it  half  or  three-quarters 
full. 


152 


BUTTER-MAKING. 


Objections  to  Farm  Separators. — Under  the  present  manner 
of  carrying  on  the  hand-separator  system,  the  quality  of  butter 
manufactured  from  the  cream  shipped  into  the  central  plants 
is  much  poorer  than  that  made  from  whole  milk.  This  is 
not  due  to  any  fault  of  the  system,  but  to  the  poor  care  which 
the  separator  and  cream  receive.  The  sepa- 
rator on  the  farm  is  frequently  kept  in  an 
unsuitable  place.  Often  it  is  located  in  the 
barn.  If  the  milk  is  separated  in  such  a 
place  it  will  absorb  odors  and  undesirable 
taints.  The  cream  is  seldom  taken  care  of 
properly  after  it  is  separated.  The  separators 
often  are  not  cleaned  well.  A  separator  can- 
not be  kept  in  good  condition  by  simply 
flushing  out  the  bowl  with  cold  water  at  the 
end  of  each  separation.  It  must  be  taken 
apart  at  the  close  of  each  skimming;  have  all 
^ne  par^s  washed  thoroughly  in  luke-wann 
scalded.  The  time  and  power  it  requires  to 
skim  the  milk  and  to  care  for  the  milk  is  in  many  instances 
considered  objectionable  to  the  system. 

Thickness  of  Cream. — The  thickness  of  cream  which  most 
butter-makers  at  central  plants  prefer  is  cream  containing 
about  30  to  40%  of  fat.  Such  cream  is  not  thick  enough 
to  cause  any  inconvenience  in  sampling  and  weighing.  It  can 
be  diluted  with  a  good  starter  and  ripened  without  getting  it 
so  thin  as  to  produce  unfavorable  conditions  for  churning. 
By  some  it  is  deemed  advisable  to  skim  even  thicker  than  this, 
up  to  50%.  Cream  containing  this  much  fat,  however,  is 
difficult  to  handle  especially  in  winter,  during  cold  weather.  It 
gets  so  stiff  that  it  is  difficult  to  pour,  and  there  is  also  danger 
of  losing  more  or  less  cream  through  its  adhering  to  the  sides  of 
the  cans. 

A  thick  cream  is  advisable  from  the  farmer's  standpoint. 
The  thicker  the  cream  is,  the  more  skim-milk  he  will  retain 
on  the  farm  for  feeding  purposes.  It  can  also  readily  be  seen 


FIG.  83  .-De 
hand  separator. 

water,  and  then 


FARM  SEPARATORS.  153 

that  if  thin  cream  is  skimmed  greater  can  capacity  is  necessary, 
and  the  express  charges  will  be  heavier  than  if  the  thicker 
cream  were  skimmed.  Rich  cream  does  not  sour  so  rapidly 
as  does  thin  cream. 


FIG.  84. — The  Reid  hand  separator.         FIG.  85. — Empire  hand  separator. 

The  thickness  of  cream  can  be  readily  ascertained  by  the 
use  of  a  Babcock  test,  which  every  farmer  should  have  in  his 
possession.  A  whole  outfit  for  testing  fat  in  cream  or  milk 


154 


BUTTER-MAKING. 


can  be  had  for  about  $8.00  from  any  creamery  supply-house. 
By  the  use  of  such  a  test,  the  farmer  can  test  his  cream  and 


FIG.  86. — Peerless  hand  separator  and  cross-section  of  bowl, 
skimmed  milk.     He  can  also  test  the  milk  of  each  individual 
cow  in  the  herd,  thereby  ascertaining  which  ones  are  profitable. 


FIG.  87. — Agos  hand  tester. 

By  the  use  of  such  a  test  on  the  farm,  the  farmer  can  test  his 
cream  daily,  and  compare  results  with  those  from  the  creamery, 


FARM  SEPARATORS. 


155 


thereby  enabling  him  to  detect  any  mistake  which  may  happen 
at  the  creamery. 

Power  for  Farm  Separators. — Hand-power    is   often   men- 


B'IG.  88. — The  Dairy  Queen  hand  separator.  FIG.  89. — Scales. 

tioned  as  an  objection  to  farm  separators.  When  a  considerable 
quantity  of  milk  is  to  be  skimmed,  it  is  certainly  hard  work 
to  skim  with  hand-power.  Windmills  could  not  well  be  used 


P 


FIG.  90. — Tread-power  attached  to  United  States  hand  separator, 
as  they  do  not  give  uniform  speed.     The  power  must  be  steady 
and    uniform.     Farm  separators    are    often    run  with    tread- 
power.     This  kind  of  power  is  very  applicable,  and  does  not  cost 


156 


BUTTER-MAKING. 


30  % 


40  # 


FIG.  91. — Showing  the  height  to  which  cream  free  from  air-bubbles  must  be 
raised  in  a  pipette  to  get  18  grams  of  cream.  It  shows  that  to  measure 
cream  in  a  pipette  is  inaccurate  in  cream  testing.  (Iowa  State  Dairy 
Com.  Report,  1903.) 


FARM  SEPARATORS. 


157 


anything  after  the  tread-power  has  once  been  purchased.    The 
power  can  be  supplied  by  using  different  kinds  of  animals. 


FIG.  92. — Showing  how  the  internal  bowl  devices  of  Westphalia  hand  sepa- 
rator are  washed.     (N.  Y.  Produce  Review  and  American  Creamery.) 

Sheep,  goats,  dogs,  and  bulls  are  used  for  this  purpose.     The 

process  usually  does  not  last  very  long,  and  it  is  not  considered 

heavy   work.      Steam    is   good    power,   but 

it   is  hardly  ever   obtainable  on    the  farm. 

Small  gasoline-engines    are    also    used    very 

successfully. 

The  machine  should  always  run  smoothly 
in  order  to  get  efficient  skimming.  It  should 
never  be  stopped  and  started  with  a  jerk. 
Start  it  slowly  and  there  will  be  less  dan- 
ger of  breaking  any  of  the  gearing  parts. 
The  bowl  and  inside  parts  should  be  kept 
from  rusting  as  described  previously  on 
page  145.  The  bearings  should  be  well  FIG.  93— Davis  hand 

.  separator. 

oiled.      It  is  a  good  plan  to  have  an  extra 

bearing  or  two   on   hand,  so    that   if   one   happens    to  wear 


158 


BUTTER-MAKING. 


out  another  one  can  be  put  in.  The  bearings  should  be 
cleaned  at  intervals.  When  kerosene  is  occasionally  used  on 
the  bearings  they  do  not  need  to  be  cleaned  so  often,  because 


FIG.  94. — Dairy  utensils  in  the  battered  condition  of  the  can  on  left  and 
with  tin  on  in  many  places  inside,  cannot  be  kept  clean  and  should  be 
discarded.  (Kansas  State  Board  of  Agriculture  Report  No.  87,  1903.) 

it  keeps  them  from  gumming.  The  machine  should  be  turned 
at  the  proper  speed,  as  indicated  in  the  directions.  A  thicker 
cream  will  result  from  rapid  turning;  consequently  more 
skimmed  milk  will  be  obtained.  Slow  turning  causes  ineffi- 
cient skimming  and  thinner  cream. 

Care  of  Cream  on  the  Farm. — The  first  step  in  the  produc- 
tion of  good  cream  is  clean  milking.  This  can  only  be  accom- 
plished when  barn,  cows,  and  utensils  are  clean.  It  is  a  good 


160  BUTTER-MAKING. 

plan  to  dampen  a  cloth,  and  wipe  off  the  cow's  udder  and  sides 
each  time  previous  to  milking.  The  milker  should  never 
wet  his  hands  while  milking.  Dust  should  not  be  stirred  up 
in  the  barn  during  milking,  as  the  dust  particles  carry  with 
them  a  large  number  of  undesirable  germs.  When  these  settle 
in  milk  they  are  likely  to  produce  taints.  If  cloth  strainers 
are  used  they  should  be  kept  scrupulously  clean.  It  is  advis- 
able not  to  use  them  at  all,  as  good  sanitary  wire-gauze  strainers 
are  inexpensive. 


I>rogeny  of  a 
single  germ  in    0 
twelve  hours 


FIG.  93. — Showing  the  effect  of  cooling  milk  on  the  growth  of  bacteria.     The 
beneficial  results  of  early  chilling  are  readily  apparent.     (From  Bui.  62, 

Wis.) 


If  these  conditions  are  complied  with,  and  the  separator 
is  kept  in  a  good  clean  condition,  the  milk  will  have  compara- 
tively few  germs  in  it.  Some  germs,  however,  will  enter  the 
milk,  and  in  order  to  keep  them  from  developing,  it  is  essential 
to  cool  the  cream  or  milk  immediately.  Low  temperature 
retards  and  practically  prevents  the  development  of  germ  life. 
It  is  a  well-known  fact  that  when  milk  is  kept  cool,  it  will 
remain  sweet  much  longer  than  if  kept  at  a  high  temperature. 
Never  mix  two  milkings  or  skimmings  unless  both  are  well 
cooled  first.  In  order  to  cool  cream  quickly,  it  should  be 
stirred  during  cooling.  The  ordinary  four-gallon  shot-gun  cans 
are  good  and  suitable  for  keeping  milk  and  cream.  They  have 
a  large  cooling  surface  in  proportion  to  their  cubical  content. 


- 

1 


FARM  SEPARATORS. 


161 


The  milk  or  cream  should  be  cooled  as  low  as  the  water  will 
cool  it.  It  is  well  to  cool  it  even  lower  than  this  if  ice  is  ob- 
tainable. In  keeping  milk,  the  temperature  should  never  go 


FIG.  97. — The   condition  of  the  cow  shown  in  this  cut  is  favorable  for  the 
accumulation  of  loose  dirt.     (Bui.  84,  111.) 

above  60°  F.  Cooling  to  50°  F.,  if  it  can  be  accomplished,  is 
much  more  desirable  for  keeping  milk  or  cream  in  good  condi- 
tion. 


162 


BUTTER-MAKING. 


If  considerable  milk  is  handled,  it  is  well  to  provide  a  milk- 
house.  It  should  be  built  large  enough  to  contain  the  sepa- 
rator, water-tank,  and  other  utensils  necessary  for  home  butter- 


FIG.  98. — A  clean  cow.     The  dirt  cannot  adhere  to  this  cow  to  so  great  an 
extent  as  to  the  one  shown  in  Fig.  97.     (Bui.  84,  111.) 

making,  such  as  a  churn  and  butter-worker.  There  should  be 
plenty  of  windows  on  all  sides  to  give  good  ventilation.  The 
water-tank  should  be  connected  directly  with  the  well,  so  that 


11 


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FARM  SEPARATORS.  167 

the  water  can  be  pumped  directly  to  the  tank  holding  the  milk 
and  cream.  From  this  place  the  water  can  be  run  out  into 
the  stock-tank.  This  arrangement  allows  the  milk  to  be  kept 
at  the  lowest  possible  temperature. 

It  is  just  as  essential  to  cool  the  milk  during  the  winter 
as  it  is  during  the  summer.  By  pumping  water  through  this  tank 
practically  all  the  time,  the  water  in  the  tank  will  be  kept  from 
freezing.  It  is  well  to  keep  the  surface  of  the  water  higher 


FIG.  103. — The  average  weight  of  dirt  which  falls  from  muddy  udders  dur- 
ing milking  is  ninety  times  as  great  as  that  which  falls  from  the  same 
udder  after  washing,  and  when  udders  are  slightly  soiled  it  is  twenty- 
two  times  as  great.  (Bui.  84,  111.) 

than  the  surface  of  the  milk  in  the  can.  This  will  prevent  the 
milk  from  freezing  so  easily.  If  the 'cold  is  too  severe;  a  tank- 
heater  can  easily  be.  secured  which  will  moderate  the  tem- 
perature a  trifle. 

Disposition  of  ttie  Cream; — -There  are  -two  ways  "of  disposing 
of  cream  on  the -farm':  (1)  selling.it  to  creameries  or  other 
parties,  and  (2)  making  it  into  butter  on  the 'farm.  The  former 
method  is  usually ;  the  ••  most  advantageous.  Creameries,  as  a 
rule,  are  better  equipped  to  control  the  quality  of  butter.  The 
price  per  pound  of  butter-fat  is  -  usually  about  2  cents  below 
"New  York  Extras.''  A  few  of  the  best  co-operative  cream- 
eries are  able  to  pay  more  than  that. 


FARM  SEPARATORS.  169 

Shipping  of  Cream. — If  cream  is  sent  or  shipped  to  cream- 
eries and  central  plants,  it  is  essential  that  it  be  delivered  as 
frequently  as  possible,  and  'that  it  be  delivered  in  cans  which 
will  help  keep  it  in  good  condition.  If  cream  is  to  be  shipped 
any  great  distance  and  be  exposed  to  the  sun,  it  is  advisable  to 
use  special  jacketed  cans,  which  retard  the  transmission  of 
heat.  It  is  a  good  plan  to  cover  the  cans  with  a  wet  sack 
>r  cloth  during  the  summer,  and  the  use  of  a  dry  sack  o.r» 


FIG.  105. — The  Buhl  milk  and  cream  can.      Fi«.  106. — A  barrel  churn. 

the  outside   in  the   winter   often    prevents    the   cream   from 
freezing. 

Making  Butter  on  the  Farm. — If  cream  is  kept  in  good 
condition  and  proper  skill  is  applied,  the  best  of -butter  can 
be  made  on  the  farm.  Theoretically,  better  butter  can  be 
made  on  the  farm  than  at  the  creamery,  because  all  conditions 
can  be  controlled  better.  This  is  not  so  in  creameries.  One 
can  of  bad  cream  mixed  with  a  quantity  of  good  cream  is  likely 
to  contaminate  and  injure  the  whole  lot.  The  cream  which 
is  to  be  made  into  butter  on  the  farm  should  be  ripened,  or 
soured,  properly  before  it  is  churned.  In  creameries,  starters 


170 


BUTTER-MAKING, 


are  used'  to  set  up  a  quick  and  desirable  fermentation  in  the 
cream.     Conditions  are  usually  such  on  the  farm  that  it  is  not 


FIG.  107. — The  Davis  swing-churn. 


FIG.  108. — Sanitary  glass  milk- 
bottle  and  cap  for  same. 


convenient  and  practical  to  use  a  starter.     In  the  summer  the 
cream  can  be  lifted  out  of  the  cold  water  the  morning  previous 


FIG.  109. — Skinner  butter-worker. 

to  churning,  and  it  will  sour  during  the  day.  In  the  evening, 
or  when  it  has  soured,  it  can  be  set  back  into  the  water  to  cool. 
The  next  morning  it  is  ready  for  churning.  In  the  winter  the 
cream  can  be  soured  by  warming  it  up  or  keeping  it  in  a  warm 
place.  If  some  good  sour  milk  is  on  hand,  it  might  be  added, 


FARM  SEPARATORS. 


171 


and  the  cream  will  sour  much  quicker.     It  is  very  essential  that 
the  cream  can  be  cooled  to  a  low  temperature  (50°  F.)  and  left 


FIG.  111. — The  Cherry  jacketed 
cream  can. 


FIG.  110. — Milk  or  cream  can 
with  agitator. 


FIG.  112. — The  Jersey  can-brush. 


at  this  temperature  for  at  least  two  hours  before  it  is  churned; 
otherwise  the  butter  is  likely  to  be  greasy  and  salvy.  Color 
and  salt  to  suit  the  market  and  season.  About  three-fourths 
to  one  ounce  of  salt  to  one  pound  of  butter  usually  gives  good 
results. 

If  a  local  trade  can  be  secured,  it  is  not  necessary  to  pack 
it  into  tubs.  Earthen  jars  are  good  to  keep  butter  in.  If  no 
local  trade  can  be  secured,  and  it  is  essential  to  ship  the  butter, 
20- or  30-pound  tubs  should  be  used.  If  a  good  quality  and 


172  BUTTER-MAKING. 

constant  supply  of  butter  can  be  secured  throughout  the  whole 
year,  it  is  an  easy  matter  to  find  an  excellent  market  for  butter 
at  hotels  or  good  restaurants.  (For  a  more  detailed  discus- 
sion of  butter-making,  see  Chaps.  XVI  and  XVII.)  Putting  up 
butter  in  prints  and  wrapping  them  in  parchment  paper  which 
bears  the  maker's  name  usually  increases  its  value. 


CHAPTER  XIII. 

PASTEURIZATION. 

Definition. — The  word  pasteurization  has  its  derivation  from 
Pasteur,  a  French  scientist.  Pasteurization  consists  in  heat- 
ing milk  somewhere  between  140°  F.  and  212°  F.  This  kills 
practically  all  germs  in  a  vegetative  state.  Since  most  of  them 
are  in  a  vegetative  condition,  the  process  kills  almost  all  the 
organisms.  The  heating  is  followed  by  rapid  cooling.  "  Sterili- 
zation" is  a  word  which  is  some  times  used  incorrectly  in  con- 
nection with  pasteurization.  Sterilization  means  that  milk  or 
any  other  substance  has  been  heated  so  often  or  to  such  a  high 
temperature  as  to  entirely  destroy  every  living  micro-organism 
present.  In  order  to  get  a  substance  thoroughly  sterilized 
without  heating  under  pressure,  it  is  essential  that  it  be  heated 
about  thirty  minutes  on  each  of  three  or  more  successive  days. 
Pasteurization  in  the  dairy  industry  was  introduced  by  Pro- 
fessor Storch  of  the  Royal  Experiment  Station,  Copenhagen, 
Denmark. 

Methods  of  Pasteurization. — 

(1)  Intermittent. 

(2)  Continuous. 

1.  Intermittent  pasteurization  is  usually  accomplished  in 
vats  or  cans.  It  is  used  nearly  exclusively  when  pasteurization 
is  practiced  on  a  small  scale,  such  as  preparation  of  starters 
in  creameries,  pasteurizing  cream  and  milk  on  the  farm,  etc. 
Intermittent  pasteurization  is  as  efficient,  and  undoubtedly  more 
so,  than  the  continuous  method.  The  substance  pasteurized 
is  usually  exposed  to  the  high  temperature  a  longer  time  than 
it  would  be  by  the  intermittent  system.  In  the  continuous 

173* 


174 


BUTTER-MAKING. 


method  of  pasteurization  the  substance  pasteurized  is  exposed 
only  to  a  sudden  temporary  heat. 

The  intermittent  process  of  pasteurization  tends  to  drive 
off  more  of  the  undesirable  taints  present  in  the  milk  or  cream. 
This  is  especially  true  when  stirred  occasionally.  If  heated  too 
long  the  cooked  flavor  is  likely  to  be  more  pronounced  than 
when  the  intarmiUeat  system  is  used.  If  exposed  very  long 


Skim  Milk  Inlet 


Skim  Milk  Tank 


FIG.  115. — Scheme  for  pasteurizing  skim-milk  by  the  use  of  exhaust-steam 
direct.     (Creamery  Journal,  by  W.  P.  McConnell,  Minn.) 

to  the  high  temperature  and  stirred  excessively  during  the 
intermittent  pasteurization,  the  butter-fat  tends  to  melt  and 
run  together,  and  show  itself  on  the  top  of  the  cream  in  the 
form  of  an  oily  layer. 

2.  The  continuous  method  of  pasteurization  is  more  practical 
for  large  amounts  of  milk  or  cream.  It  is  used  almost  without 
exception  in  pasteurizing  cream,  whole  milk,  and  skim-milk 
at  creameries.  Neither  one  of  the  two  systems  destroys  spores. 
The  intermittent  system  is  the  most  effective  because  both 


PASTEURIZATION.  175 

time  and  temperature  are  under  control.  Various  pasteuriz- 
ing machines  are  in  use,  and  it  is  not  within  the  province  of 
this  work  to  recommend  any  machine.  A  few  words  in  regard 
to  the  principles  which  affect  proper  pasteurization  will  serve 
a  better  purpose. 

SELECTION  OF  PASTEURIZERS. 

Improper  pasteurization  is  worse  than  none  at  all.  If 
pasteurization  is  done  at  all,  it  is  essential  that  it  be  properly 
accomplished. 

There  are  two  things  to  be  sought  when  purchasing  a  pas- 
teurizer; viz.,  (1)  durability  and  capacity,  and  (2)  economic 
efficiency. 

1.  Durability  and  Capacity. — The    structure  of  most   pas- 
teurizing machines  is  simple  and  substantial.    They  do  not 
wear  out  like  a  complex  piece  of  machinery.    It  is  essential 
that  the  machine  be  strongly  made.     Heating-walls  and  other 
portions  should  be  made  heavy  enough  to  be  consistent  with 
its  use,  and  of  a  substance  which  will  conduct  heat  rapidly. 
Nearly  all  the  types  of  pasteurizers  are  made  in  different  sizes 
to  suit  the  demands. 

2.  Economic  Efficiency. — Obtaining  efficient  pasteurization 
economically  is  the  most  important  question.     It  is  important 
in  this  connection  because  it  depends  upon  so  many  conditions 
which  the  operator  has  under  control.     The  degree  of  con- 
ductivity of  heating-surface  during  operation,  may  in  one  sense 
include  most  of  the  essential  factors  which  affect  pasteurization. 
This  in  turn  depends  upon  a  number  of  conditions  which  are  as 
follows : 

(1)  Kind  of  material   from  which   the   heating-surface  is 
manufactured. 

(2)  Degree  of  adhesiveness  of  milk  or  cream  on  heating- 
surface. 

(3)  Thickness  of  layer  of  condensed  steam,  on  steam  side  of 
heating-surface. 

(4)  Difference  in  temperature  on  each  side  of  heating-surface. 


176 


BUTTER-MAKING. 


(5)  Proper  utilization  of  steam  turned  intq.^the  pasteurizer. 

(1)  Heating-surface. — It  is  a  well  known /fact  that  some 
metals  will  conduct  heat  better  than  others.  The  relative  heat 
conductivity  of  the  two  substances  used  chiefly  for  pasteurizers 
viz.,  copper  and  tin,  is  .918  and  .145  respectively.  This 
means  that  copper  will  conduct  heat  nearly  seven  times  faster 
than  tin  of  the  same  thickness. 


FIG.  116. — The  Reid  pasteurizer. 

In  connection  with  this  it  should  be  mentioned  that  stability 
and  durability  of  the  substance  must  also  be  taken  into  con- 
sideration. A  heating-surface  made  from  copper  may  be  nearly 
seven  times  as  thick  as  that  made  from  tin,  and  still  transmit 
as  much  heat  as  the  tin  surface.  From  this  it  can  be  seen  that 
a  heating  wall  made  from  copper  can  be  increased  slightly  in 
thickness,  and  thus  aid  in  stability,  without  affecting  the  degree 
of  heat  conductivity  of  the  wall  very  much.  The  heating- 
surface  must  be  strong  enough  to  withstand  a  slight  steam  pres- 
sure, otherwise  the  heating  wall  is  likely  to  collapse  or  cave 
in  in  case  of  slight  variation  in  the  steam  pressure.  It  is  not 


P.-l  S  TE  URIZA  TION. 


Ill 


an  uncommon  c  ^currence  to  have  the  heating  wall  of  a  pasteur- 
izer burst.  This  could  be  prevented  by  connecting  a  safety,  or 
pressure,  valve,  to  the  pasteurizer. 

(2)  Degree  of  Adhesiveness.  —  Roughness,  due  to  either 
defects  in  the  metal  itself,  or  to  milk  or  cream  being  burned 
on  the  heating-surface,  is  a  serious  defect.  Such  a  condition 


FIG.  117. — The  Simplex  regenerative  pasteurizer  (apart). 

causes  particles  of  milk  or  cream  to  move  very  slowly  over  the 
heating-surface;  it  tends  to  roll  in  much  the  same  way  as 
drops  of  liquids  do  when  caused  to  flow  over  a  slanting  dry 
rough  surface.  As  a  consequence  more  and  more  casein  will 
adhere.  The  thicker  the  layer  of  foreign  matter  is  on  the 
heating-surface,  the  greater  the  difficulty  in  getting  the  greatest 
efficiency  from  the  pasteurizer. 

It  is  important  that  the  milk  or  cream  be  forced  over  the 
heating-surface  with  greater  rapidity  than  could  result  from 
its  own  gravity.  On  heaters  or  pasteurizers,  where  milk  flows 


178 


BUTTER-MAKING. 


over  the  heating-surface  only  by  force  of  its  own  gravity,  a 
heavy  layer  of  curd  usually  adheres.  This  is  due  to  the  fact 
that  certain  portions  of  the  milk  are  exposed  to  the  excessive 
heating  too  long,  while  if  caused  to  move  rapidly  it  does  not 
remain  in  contact  with  one  portion  of  the  heating-surface  long 
enough  to  cause  it  to  adhere  to  so  great  an  extent. 


FIG.  118. — The  Simplex  regenerative  pasteurizer  (assembled). 

The  condition  of  the  milk  or  cream  has  some  influence  upon 
the  degree  of  adhesiveness  of  curd  on  the  heating-surface. 
Sour  and  coagulated  milk  adheres  or  burns  on  to  a  greater 
extent  than  does  milk  or  cream  in  good  condition.  This  is 
evidently  due  to  the  lesser  fluidity  of  the  sour  milk,  and,  as  a 
consequence,  it  does  not  move  over  the  heating-surface  so 
rapidly,  and  therefore  burns  on.  Milk  which  contains  a  great 
deal  of  air  or  scum  also  adheres  to  the  heating-surface  much 


PASTEURIZATION. 


179 


more  readily  than  milk  containing  less  air.  If  pumps  are  used 
for  pumping  the  milk,  it  is  well  to  admit  as  little  air  into  the 
milk  as  possible.  This  can  be  accomplished  by  keeping  plenty 
of  milk  in  the  tank  which  feeds  the  pump,  or  by  having  a  float 
which  will  close  the  inlet  to  the  pasteurizer  as  soon  as  the  tank 
is  emptied.  If  the  speed  of  the  agitator  in  the  pasteurizer 
is  great  enough,  the  scum  is  forced  towards  the  center.  For 


FIG.  119. — The  Jensen  pasteurizer. 


some  time  it  was  thought  that  only  the  best  sweet  milk  could 
be  pasteurized  by  the  intermittent  process  of  pasteurization. 
It  is  well  known  that  when  a  sample  of  milk  reaches  a  certain 
degree  of  acidity  it  coagulates  upon  heating.  It  was  thought 
that  by  the  continuous  method  of  pasteurization  this  would 
interfere  with  getting  proper  results.  Experiment,  however, 
shows  that  the  coagulated  sour  cream  and  milk  can  be  suc- 
cessfully pasteurized,  but  it  is  still  a  fact  that  the  better  con- 
dition the  milk  or  cream  is  in,  the  easier  it  can  be  pasteurized 


180 


BUTTER-MAKING. 


and  the  better  the  results  are.  If  pasteurization  is  not  prop- 
erly conducted,  often  the  sour  milk  and  cream  coagulate  and 
get  very  lumpy.  This  takes  place  chiefly  when  pasteurization 
is  attempted  at  a  comparatively  low  temperature,  at  a  slow 
rate  of  speed  of  the  agitator  in  the  pasteurizer,  and  when  there 
is  about  from  .3%  to  .4%  acidity  in  the  cream  or  milk.  Sour 
thin  cream — less  than  23%  fat — does  not  pasteurize  successfully. 
In  case  there  is  any  danger  of  sliminess  taking  place  during 
pasteurization,  the  heat  should  be  applied  as  quickly  as  possible. 

Only  a  thin  layer  of  cream 
should  be  exposed  to  the 
heating-surface  at  one  time. 
Flashy,  quick  heat  tends  to 
prevent  this  slimy  condition. 
The  speed  of  the  stirrer  should 
be  increased,  if  possible,  when 
such  cream  is  being  pasteur- 
ized. 

By  greasing  the  inside  of 
the  pasteurizer,  or  the  heat- 
ing-surface, a  trifle  previous 
to  pasteurization,  the  burning- 

on  can  be  prevented  in  part.     The  casein  that  adheres  can 
be  more  easily  removed  than  if  no  grease  were  used. 

(3)  Thickness  of  Layer  of  Condensed  Steam. — At  first  glance 
one  might  come  to  the  conclusion  that  the  small  amount  of 
steam  which  is  constantly  being  condensed  upon  and  adhering 
to  the  steam  side  of  the  heating-surface  is  not  sufficient  to 
cause  any  difference  in  the  efficiency  of  the  pasteurizer.  Ex- 
periments conducted  by  Dr.  Storch  of  the  Royal  Experiment 
Station,  Copenhagen,  Denmark,  show  that  this  condensed  steam 
greatly  resists  the  transmittance  of  heat.  The  comparative 
heat  conductivity  of  water  and  Copper  is  .0016  and  .9  respec- 
tively, as  found  by  Dr.  Storch.  It  will  thus  be  seen  that  copper 
is  600  times  as  good  a  conductor  of  heat  as  water  is.  This  would 
mean  that  a  quiet  layer  of  water  3  millimeters  in  thickness 


FIG.  120. — The  Miller  pasteurizer. 


PASTEURIZATION. 


181 


would  have  the  same  resistance  to  heat  as  a  layer  of  copper 
2  meters  in  thickness.  Consequently  a  very  thin  layer  of  water 
or  condensed  steam  on  the  sides  of  the  heating-wall  would 
greatly  interfere  with  the  economic  efficiency  of  a  pasteurizer. 
In  order  to  overcome  this  difficulty  drip-rings  were  circled 
round  the  drum  of  the  pasteurizer  at  intervals  on  the  steam  side 
of  the  heating-surface.  The  first  rings  put  around  the  pasteurizer 
were  narrow  smooth  bands.  These  did  not  give  entire  satisfac- 
tion, as  the  condensed  water  from  the  top  rings  would  drip  on 
the  edge  of  the  lower  ones,  and  cause  the  water  to  splatter  over 
the  side  of  the  heating- wall.  Another  kind  of  ring  was  then  in- 
vented, which 
was  thin,  nar- 
row, and  saw- 
teeth-like in 
shape.  These 
rings  were  fast- 
ened to  the 
heating-wall  at 
proper  inter- 
vals at  an  angle 
of  45°.  The 


The  Farrington  pasteurizer. 


rings  were    so 
arranged    that 

the  drops  of  condensed  water  escaping  from  the  end  of  each  saw 
tooth  would  fall  in  the  hollow  between  the  teeth  in  the  lower  rings 
and  thus  prevent  any  splattering  of  the  water  against  the  heating- 
Avail.  These  contrivances  greatly  increased  the  efficiency — as  high 
as  48% — and  the  capacity  of  the  pasteurizer  experimented  upon. 
(4)  Difference  in  Temperature  on  Each  Side  of  the  Heating- 
surface. — The  difference  in  the  temperature  on  each  side  of  the 
heating-surface  has  a  great  effect  upon  the  rapidity  with  which 
the  heat  passes  through  the  wall.  The  lower  the  temperature 
is  on  the  milk  side  the  more  rapidly  does  the  heat  pass  through; 
and  the  higher  the  temperature  of  the  milk  is,  the  pressure  on 
the  steam  side  being  the  same,  the  more  slowly  the  heat  passes 
through  the  heating-wall.  This  would  at  first  lead  us  to  be- 


182  BUTTER-MAKING. 

lieve  that  the  last  few  degrees  the  milk  is  being  heated  are  the 
most  expensive;  but  if  the  steam  is  properly  guarded  from 
being  condensed,  or  wasted,  it  does  not  cost  any  more  to  heat 
the  milk  the  last  few  degrees  than  it  does  to  heat  the  first  degrees. 
While  the  temperature  on  the  milk  side  is  low,  much  more 
steam  is  consumed,  and  it  is  also  used  more  rapidly.  During 
the  last  heating  of  the  milk  or  cream  less  steam  is  being  con- 
densed and  the  condensing  proceeds  more  slowly. 

When  the  temperature  on  the  steam  side  is  220°  F.  and  on 
the  milk  side  is  40°  F.  during  the  same  time,  twice  as  much 
heat  will  pass  through  the  heating  wall  as  if  the  temperature 
of  the  milk  side  were  130°  F.  In  the  first  case  the  difference 
in  temperature  on  both  sides  would  be:  220-40=180°  F.  In 
the  second  instance  it  would  be:  220 ^130  =  90°.- F. 

(5)  Proper  Utilization  of  Steam  Turned  into-  the  Pasteurizer. 
—The  cost  of  pasteurization  will  evidently  vary  under  different 
conditions  and  with  different  kinds  of  pasteurizers.  In  order 
to  reduce  the .  cost  of  pasteurization  to  the  minimum,  it  is 
essential  that  all  steam  turned  into  the  pasteurizer  be  properly 
utilized.  The  pasteurizer,  as  well  as  the  steam-pipes,  should 
be  properly  insulated  in  order  to  prevent  unnecessary  conden- 
sation of  steam.  According  to  experiments  carried  on  by 
Dr.  Storch,  all  steam  contains  more  or  less  air.  By  making 
a  device  on  the  pasteurizer  for  the  escape  of  this  air  better 
results  were  obtained.  By  the  use  of  such  a  vent  it  was  made 
possible  to  heat  1890  pounds  of  water  from  52°  F.  to  185°  F., 
while  without  this  air  device,  and  with  the  same  amount  of 
heat,  only  1467  pounds  of  water  were  heated.  That  is,  by 
this  device  he  made  a  gain  of  30%  in  the  heating  efficiency 
of  the  pasteurizer.  The  contrivance  used  was  simply  a  pipe 
attached  to  the  bottom  of  the  pasteurizer  and  extending  down 
below  the  pasteurizer  about  2  feet,  then  turned  or  bent,  and 
brought  up  vertically  a  few  inches  above  the  bottom  of  the 
pasteurizer.  The  mouth  of  the  pipe  was  then  turned  over. 
This  pipe  accomplishes  two  purposes.  It  removes  condensed 
water  from  the  pasteurizer,  and  also  the  accumulated  air.  It 


PASTEURIZATION.  183 

is  also  essential  that  the  pasteurizer  should  not  leali.  All  the 
steam  turned  into  the  pasteurizer  should  be  condensed  before  it 
is  allowed  to  escape. 

The  Cost  of  Pasteurization.— Dr.  Storch  in  his  43rd  report  of 
the  Royal  Agricultural  Experiment  Station,  at  Copenhagen, 
Denmark,  reports  that  it  requires  80  pounds  of  steam  to  heat 
1000  Danish  pounds  of  milk  from  40°  C.  to  85°  C.  This  would 
be  equivalent  under  American  conditions  to  about  90  pounds  of 
steam  to  pasteurize  1000  pounds  of  milk  from  90°  F.  to  185°  F. 

According  to  good  authority  it  takes  1  pound  of  lump  coal 
to  produce  6  pounds  of  steam.  Calculating  from  this,  it  will 
take  15  pounds  of  coal  to  produce  90  pounds  of  steam.  If 
coal  costs*$4.00  per  ton,  the  cost  of  15  pounds  of  coal  would 
be  3  cents.  If  the  milk  tests  3.6%  fat,  and  calculated  on 
one-sixth  overrun,  the  1000  pounds  of  milk  would  produce 
about  42  pounds  of  butter.  The  cost  of  pasteurizing  the  milk 
producing  42  pounds  of  butter  is  then  3  cents,  and  the  cost 
of  pasteurization  per  pound  of  butter  would  be  .07  of  a  cent. 

Taking  into  consideration  the  cost  of  cooling,  and  counting 
on  about  .03  of  a  cent  for  leaks  involved  during  the  process, 
the  cost  of  pasteurizing  per  pound  of  butter  would  be  about 
.1  of  a  cent.  As  a  rule,  the  major  portion  of  the  cooling  is  done 
with  water,  which  at  most  creameries  costs  little  or  nothing. 
For  this  reason  the  cost  of  cooling  has  been  omitted. 

Advancement  of  Pasteurization. — During  the  last  few  years 
pasteurization  has  gained  favor  with  the  American  creamery 
operators.  It  has  been  thoroughly  demonstrated  that  if  the  best 
product  is  to  be  manufactured  it  is  absolutely  essential  that  the 
operator  have  complete  control  of  the  fermentations  in  the 
cream  or  milk.  This  control  of  the  fermentation  can  best  be 
accomplished  by  the  process  of  pasteurization.  Pasteurization 
has  been  gaining  favor  with  the  creamery  operators  owing  to 
its  own  merits.  The  Danish  Government  compelled  the  pas- 
teurization of  milk  or  cream  as  a  safeguard  against  tuberculosis. 
It  was  found  not  only  that  the  system  was  efficient  in  this 
respect,  but  also  that  it  produced  a  more  uniform  product,  with 


184  BUTTER-MAKING. 

better  keeping  qualities.  At  the  present  time  nearly  all  of  the 
central  plants  are  pasteurizing  their  cream  to  a  greater  or  less 
extent. 

Advantages  of  Pasteurization. — The  advantages  of  pasteur- 
ization are  many,  but  the  chief  ones  are  as  follows: 

(1)  It   enables    the   butter-maker    to    produce    a   uniform 
quality  of  butter.     If  most  of  the  germs  are  destroyed  by 
pasteurization,  and  a  pure  culture  added  to  the  cream,  the 
ferments  added  will  be  in  full  control.     If  nothing  but  a  desir- 
able kind  of  germ  is  added,  it  follows  that  the  product  will  be 
uniform   in  quality    In  this  way  practically  the  same  results 
can  be  obtained  from  day  to  day. 

(2)  It  eliminates  many  of  the  undesirable  taints  in  the  milk. 
Especially  is  this  effect  noticeable  during  the  fall,  when  cows 
are  liable  to  eat  weeds  that  taint  the  milk.     Xo  matter  how 
well  milk  has  been  taken  care  of,  it  usually  contains  taints 
which,  when  pasteurized  will  be  partially  eliminated  from  the 
milk. 

(3)  It    destroys   most  of   the   germs.      This  is   important 
for  two  reasons.     It  destroys  most  of  the  germs  which  effect 
the  quality  of  the  butter,  and  it  also  destroys  the  pathogenic 
germs,  thus  preventing  the  spread  of  diseases,  such  as  tuber- 
culosis, typhoid  fever,  etc. 

(4)  The  butter-maker  can  control  the  fermentation  in  cream 
much  more  easily  when  pasteurization  is  employed.     It  has 
been  demonstrated   that    the  quality  of  the  butter  depends 
in  large  measure  upon  the  kind  of  fermentation.     When  the 
fermentation  in  the  cream  is  thoroughly  controlled,  a  better 
quality  of  butter  can  be  produced.     When  the  milk  is  in  first- 
class  condition,  fully  as  good  butter  can  be  produced  without 
the  use  of  pasteurization,  but  it  does  not  keep  so  well.     Milk 
may  appear  to  be  in  good  condition,  and  yet  at  the  same  time 
contain  germs  which  are  detrimental  to  the  quality  of  the 
butter. 

It  is  at  the  present  time  a  matter  of  dispute  whether  milk 
and  cream  in  a  really  sour  and  poor  condition  is  benefited 


PASTEURIZATION.  185 

jnuch  by  pasteurization.  The  flavor  of  the  butter  made  from 
such  pasteurized  cream  is  usually  not  improved  very  much. 
However,  the  keeping  quality  of  butter  made  from  poor  cream 
pasteurized  is  usually  better  than  if  no  pasteurization  had  been 
employed.  If  the  inferior  quality  of  cream  and  milk  can  be 
pasteurized,  neutralized  with  an  alkali,  such  as  powdered  chalk 
or  bicarbonate  of  soda,  then  inoculated  with  a  desirable  species 
of  bacteria  and  re-ripened,  the  quality  of  butter  can  be  im- 
proved several  points.  But  experiments  carried  on  at  the 
Iowa  Experiment  Station  indicate  that  the  improvement  in  the 
quality  of  butter  is  not  very  permanent.  Immediately  after  it 
has  been  made  there  is  a  very  distinct  improvement  in  the 
quality  of  the  butter  from  such  cream,  sometimes  as  much  as 
five  points.  But  for  some  reason  butter  from  cream  that  has 
been  neutralized  in  such  a  way  does  not  seem  to  keep  well. 
Some  days  after  its  manufacture  it  begins  to  lose  decidedly  in 
flavor  and  to  assume  a  very  rank  condition.  For  this  reason 
this  method  of  treating  poor  cream  has  not  been  generally 
advocated.  The  deterioration  that  takes  place  in  such  butter 
after  standing  seems  to  be  due  to  chemical  changes  rather 
than  to  biological  changes.  The  butter  referred  to  was  kept 
in  a  refrigerator  at  a  temperature  of  about  50°  F. ;  if  the  rancid 
flavors  were  due  to  the  growth  of  micro-organisms,  they  should 
not  reveal  themselves  in  so  short  a  time. 

(5)  Pasteurization  increases  the  keeping  quality  of  butter. 
This  is  one  of  the  greatest  advantages  of  employing  pasteuriza- 
tion in  butter-making.     The  advantage  of  keeping  butter  from 
the  time  of  large  supply  and  small  prices  to  the  time  of  small 
supply  and  higher  prices,  makes  pasteurization  in  butter-making 
of  vital  importance  in  improving  the  keeping  qualities  of  butter. 
Butter  made  from  good  pasteurized  cream  and  washed  in  pas- 
teurized water  will  keep  about  twice   as  long  as  butter  made 
from  the  same  kind  of  cream  not  pasteurized  and  washed  in 
unpasteurized  water. 

(6)  If   milk  is   pasteurized   previous   to   skimming,   closer 
skimming  can  be  obtained  than  if  the  milk  were  heated  to  a 


186 


BUTTER-MAKING. 


comparatively  low  temperature.     The  reason  for  this  has  been 
previously  explained. 

Disadvantages  of  Pasteurization. — The  cost  and  additional 
trouble  involved  in  pasteurizing  are  undoubtedly  the  chief 
disadvantages  that  could  be  brought  up  against  pasteurization. 
As  was  calculated  above,  the  cost  of  pasteurization,  after  the 
pasteurizer  has  once  been  purchased,  is  only  .1  of  a  cent  per 
pound  of  butter.  This  cost  would  be  reduced  considerably 
if  the  cream  only  were  pasteurized,  and  increased  if  the  cream 
and  skim-milk  were  pasteurized  in  separate  machines.  The 


1st 
hcore  week 


2nd 
week 


5th        Gth 
week    week 


9th 
week 


10th      llth       12th      13th       lith 
teek     week     week     week     week 


Score 


96 


94 


\ 


86 


80 


X 


FIG.  121. — Comparison  of  deterioration  of  butter  made  from  pasteurized 
cream  and  wash-water  to  that  made  from  unpasteurized  cream  and 
water,  illustrated  graphically.  (Bui.  71,  Iowa.) 

initial  cost  of  the  pasteurizer  is  the  great  mountain  to   over- 
come in  the  introduction  of  pasteurization  in  creameries. 

When  pasteurization  is  employed  in  butter-making,  it  is 
absolutely  essential  that  the  greatest  degree  of  skill  and  in- 
telligence be  applied.  If  care  is  not  taken  pasteurization  is 
likely  to  produce  a  poorer  quality  of  butter  than  is  the  case 
when  no  pasteurization  is  employed.  Especially  is  this  true 
when  sour  or  abnormal  cream  and  milk  are  being  pasteurized, 
and  little  or  no  starter  is  used. 


CHAPTER  XIV. 

CREAM-RIPENING. 

Definition.  —  By  cream-ripening  we  mean  the  treatment 
cream  receives  from  the  time  it  is  put  into  the  ripening-vat 
until  it  is  put  into  the  churn;  and  also  the  chemical,  biological, 
and  physical  changes  cream  undergoes  during  the  same  time. 

OBJECTS  OF  RIPENING. 

(i)  To  Produce  Flavor  and  Aroma. — The  chief  object  of 
cream-ripening  is  to  secure  the  desirable  and  delicate  flavor 
and  aroma  which  are  so  characteristic  of  good  butter.  These 
flavoring  substances,  so  far  as  known,  can  only  be  produced  by  a 
process  of  fermentation.  It  is  a  well  known  fact  that  the  best 
flavor  in  butter  is  obtained  when  the  cream  assumes  a  clean, 
pure,  acid  taste  during  the  ripening.  For  this  reason,  it  is 
essential  to  have  the  acid-producing  germs  predominate  during 
the  cream  ripening;  all  other  germs  should  if  possible  be 
excluded  or  suppressed. 

It  has  not  yet  been  proved  that  any  one  particular  species 
of  bacteria  is  responsible  for  the  production  of  the  flavors,  but  it 
is  agreed  by  all  that  the  flavoring  substances  developed  during 
the  ripening  of  cream  are  decomposition  products  of  bacterial 
growth,  and  that  the  types  producing  the  lactic  acid  are  the 
most  desirable  ones  to  have  present.  There  are  a  great  many 
bacteria  in  milk  and  cream  which  will  produce  acid.  Over  one 
hundred  species  have  been  studied  and  described.  There  seems, 
however,  to  be  a  comparatively  few  of  those  which  produce 
the  best  results. 

187 


188 


BUTTER-MAKING. 


It  seems  that  during  cream-ripening  the  development  of 
acid,  aroma,  and  flavor  go  hand  in  hand.  This  does  not  neces- 
sarily indicate  that  they  are  produced  by  the  same  cause.  It 
is  possible  that  the  flavor  and  aroma  substances  are  chemically 
produced  from  the  various  by-products  of  the  germs. 

Bacteriologists  do  not  agree  as  to  what  species  of  bacteria 
is  responsible  for  the  high  quality  of  flavor  and  aroma  of  butter. 
Conn  *  claims  that  the  germs  which  act  upon  the  nitrogenous 


FIG.  122. — The  Me  Area  vy  cream- 
ripening  vat. 


FIG.  123. — The  Miller  cream-ripening 
vat. 


matter  of  milk  are  associated  'with  the  lactic-acid-producing 
bacteria  in  the  production  of  desirable  butter  flavors.  Weig- 
man  asserts  that  the  best  results  are  obtained  when  a  Variety 
of  species  work  together  in  the  cream.  He  has  isolated  a  single 
species  of  germ  which  produced  alcohol  and  lactic  acid  as 
by-products,  and  which,  according  to  experimental  evidence 
deduced  by  him,  is  capable  of  producing  the  delicate  butter 
flavors.  Freudenrich  has  also  studied  a  species  of  germ  which 
produced  alcohol  and  lactic  acid  as  by-products,  and  was  able 
to  produce  the  characteristic  butter  flavors.  Eckles  has  studied 
this  question  of  flavor  production  during  cream-ripening.  He 
comes  to  the  conclusion  that  the  flavor  and  aroma  substances 

*  Storr  Station,  Conn. 


CREAM  RIPENING.  189 

developed  during  cream-ripening  may  be  produced  by  a  variety 
of  acid-producing  bacteria.  He  asserts  that  of  the  species 
tried  the  most  common  milk-souring  organism  (Bacterium  lac- 
tarii)  gave  the  most  satisfactory  results  as  a  culture  for  ripen- 
ing cream.  Storch,  who  has  perhaps  studied  this  question 
more  than  any  one  else,  maintains  that  the  germs  producing 
lactic  acid  are  essential  to  good  cream -ripening,  and  that  the 
flavor  and  aroma  products  are  the  results  of  the  joint  action  of 
a  great  many  species  of  lactic-acid-producing  germs.  Tiemann  * 
finds  that  an  addition  of  a  small  amount  of  hydrochloric  acid 
to  the  cream  does  not  produce  the  characteristic  flavor,  and  in- 


FIG.  124. — The  Wizard  cream-ripening  vat. 


dicates  that  the  process  of  fermentation  is  necessary  to  get 
the  proper  flavors.  Dean,  of  the  Ontario  Agricultural  College, 
has  recently  reported  that  the  flavoring  substances  can  be 
developed  in  the  starter,  then  added  to  the  cream.  The  re- 
sulting butter  has  as  good  or  a  trifle  better  flavor  than  that 
which  undergoes  a  process  of  fermentation  by  ripening  in  the 
usual  way. 

From  the  investigations  quoted  above  it  will  be  seen  that 
there  is  some  doubt  yet  as  to  the  specific  origin  of  the  flavor 
and  aroma  substances  developed  during  cream-ripening.  It 
is  also  not  known  for  certain  just  what  those  flavoring  sub- 

*  Milch-Zeitung,  Vol.  13,  p.  701. 


190 


BUTTER-MAKING. 


stances  are.  They  are  evidently  volatile,  ether-like  compounds, 
which  are  produced  by  bacterial  growth  during  the  ripening 
process.  Few  years  ago  it  was  thought  that  these  flavoring 
substances  were  due  entirely  to  the  oxidation  process,  and 
that  in  order  to  get  these  flavors  in  butter  it  was  necessary  to 
expose  the  cream  to  pure  air  during  the  ripening.  It  has  now 
been  proved  that  air  might  be  excluded  from  the  cream-vat, 
and  still  good  results  be  obtained.  This  does  not,  however, 
demonstrate  that  oxygen  is  not  essential  for  the  best  results  in 
cream-ripening.  All  cream  contains  more  or  less  oxygen  in 
solution.  It  has  been  thought  that  the  oxygen  that  cream 
holds  in  solution  may  favor  the  growth  of  the  desirable  germs 
in  cream,  and  that  as  soon  as  this  has  been  utilized,  conditions 
may  become  unfavorable  for  the  desirable  germs  and  favorable 
for  the  undesirable  germs. 

Practically,  all  the  investigators  agree  that  the  flavor  and 
aroma  substances  which  are  characteristic  of  butter  and  which 
are  developed  in  ripening  cream,  are  due  to  bacterial  growth, 
and  that  the  germs  producing  lactic  acid  are  the  most  desirable 
ones.  We  quote  the  following  instances  to  show  what  effect 
some  species  of  bacteria  may  have  upon  the  quality  of  butter, 
when  present  in  the  cream: 


Number. 

Species  Used  for  Starter. 

Score  on  Flavor, 
45  Perfect. 

Selling  Price, 
per  Pound. 

1 

Bacterium  lactarii  

39 

$   20 

2 

Bacillus  subtillis  

31 

14 

These  two  samples  of  butter  were  made  from  the  same 
kind  of  cream  which  was  pasteurized  and  inoculated  with 
starters  from  the  different  germs  as  indicated  in  the  table.* 
The  butter  ripened  with  Bacillus  subtillis  sold  for  6  cents 
per  pound  less  than  the  other,  a  difference  of  nearly  one-third 
in  value,  due  to  the  character  of  fermentation  in  the  cream 
during  ripening.  Therefore  in  developing  the  proper  flavors  in 


*  Bui.  40,  Iowa  Experiment  Station. 


CREAM-RIPENING. 


191 


butter,  it  is  very  essential  that  the  undesirable  germs  be  ex- 
cluded or  suppressed  and  that  the  conditions  for  the  develop- 
ment of  the  desirable  typical  acid  ferments  in  the  cream  be 
made  as  favorable  as  possible.  The  undesirable  ferments  may, 
as  a  whole,  be  said  to  be  those  which  act  upon  the  nitrogenous 
matter,  or  those  which  cause  ordinary  decay.  They  very  likely 
come  from  filth  in  the  barn,  milking  utensils,  unclean  milkersr 


FIG.  125. — The  new  Jensen  cream-ripening  vat.     (Peerless.) 

and  unclean  and  dusty  barns.  Abnormal  fermentations  of 
cream,  such  as  ropy,  bitter,  chromogenic  fermentations,  etc., 
are  of  course  undesirable  ferments.  For  kinds  and  classifica- 
tion of  germs  in  milk,  see  Chapter  IV  on  Bacteria,  and  Chapter  V 
on  Abnormal  Milk. 

(2)  To  Increase  Churnability  of  Cream. — Cream-ripening 
is  not  essential  in  order  to  complete  the  churning  process,  but 
ripened  cream  will  churn  more  easily  and  more  completely  than 
unripened  cream,  under  the  same  conditions.  This  is  due  to  a 


192  BUTTER-MAKING. 

lessening  viscosity  of  the  cream.  The  ripening  process  causes 
the  cream  to  become  thicker  but  less  viscous.  Undoubtedly 
the  acid  developed  during  the  ripening  process  tends  to  cut 
the  membrane  supposed  to  surround  the  fat-globules.  The 
reduced  viscosity  of  the  cream  renders  it  easier  for  the  globules 
to  move  and  unite  in  the  serum  when  exposed  to  agitation  in 
the  churn.  It  is  possible  to  churn  ripened  cream  in  a  thinner 
state  and  at  a  lower  temperature  than  unripened  cream. 

Cream  which  has  been  ripened  to  a  normal  degree  of  acidity, 
also  allows  of  a  more  complete  churning  than  unripened  cream. 


FIG.  126. — The  Boyd  cream-ripening  vat. 

If  cream  is  properly  ripened,  and  churned  at  a  medium  low 
temperature,  it  is  possible  to  churn  so  that  the  buttermilk  con- 
tains only  about  .1%  of  fat  by  the  Babcock  test;  while  if  sweet 
cream  is  being  churned  under  the  same  conditions,  the  butter- 
milk will  contain  more  than  this.  This  is  undoubtedly  due  to 
the  fact  that  in  sweet  cream  the  viscosity  is  so  great  that  it 
prevents  the  minute  fat-globules  from  uniting  when  agitated 
in  the  churn,  while  in  sour  milk  the  viscosity  has  been  largely 
removed.  Sour  cream  is  thicker  than  ripe  cream,  but  less 
viscous.  This  facilitates  the  coalescence  of  the  fat-globules 
when  exposed  to  agitation. 

(3)  To  Increase  the  Keeping  Quality  of  Butter. — It  has  been 
demonstrated  by  several  investigators  that  the  keeping  quality 
of  butter  depends  chiefly  upon  the  number  and  kinds  of  germs 
present  in  the  butter  after  its  manufacture.  In  order,  there- 


CREA  M -RIPEN  ING. 


193 


fore,  to  produce  butter  with  good  keeping  qualities  it  becomes 
essential  to  exclude  or  suppress  all  germs  which  deteriorate 
butter.  It  is  not  of  so  great  importance  to  exclude  germs 
which  do  not  injure  the  keeping  quality  of  butter.  The  germs 
that  produce  lactic  acid  do  not  cause  direct  deterioration 
cf  butter.  This  has  been  demonstrated  by  Jensen.* 

When  cream  has  been  properly  ripened,  it  is  practically  a 

gr 


FIG.  127. — The  old  Jensen  cream-ripening  vat. 

pure  culture  of  lactic-acid-producing  germs,  while  sweet  un- 
pasteurized  cream  contains  a  bacterial  flora,  consisting  of  a 
great  many  types  of  desirable  and  undesirable  germs.  It 
should  be  mentioned  in  connection  with  this,  that  it  is  only 
properly  ripened  cream  that  contains  with  any  certainty,  a 
preponderance  of  germs  producing  lactic  acid.  If  the  cream 
is  over-ripe,  the  undesirable  bacteria  may  also  gain  the  ascen- 


*  Landwirtschaftliches  Jahrbuch  der  Schweiz. 


194  BUTTER-MAKING. 

dency  of  the  desirable.  When  such  overripened  cream  is 
churned,  these  undesirable  germs  are  transmitted  to  the  butter, 
and  cause  deterioration.  If  the  butter  is  churned  from  properly 
ripened  cream,  and  at  the  proper  ripening  stage,  and  the  butter 
washed  in  purified  water,  very  few  undesirable  germs  are  trans- 
mitted to  the  butter,  and,  as  a  consequence,  it  keeps  better. 

Ripening  Temperature  of  Cream. — In  practice,  the  ripening 
temperature  of  cream  varies  within  wide  limits.  Some  makers 
prefer  to  ripen  cream  at  a  temperature  of  about  80°  F.,  others 
ripen  at  about  70°  F.,  and  still  others  prefer  to  ripen  at  a  tem- 
perature between  60°  and  70°  F.  Undoubtedly,  the  conditions 
in  the  creamery  will  to  some  extent  govern  the  ripening  tem- 
perature. Up  to  a  certain  limit  the  higher  the  temperature, 
the  quicker  the  ripening  process.  In  some  instances,  it  is 
desirable  to  ripen  and  cool  cream  in  a  few  hours,  and  then 
churn  the  same  day.  Under  such  conditions  a  comparatively 
high  ripening  temperature  is  undoubtedly  preferable,  as  the 
cream  will  sour  more  quickly  at  such  a  temperature.  Un- 
doubtedly good  butter  can  be  made  at  any  of  the  temperatures 
mentioned  above,  but  when  we  are  to  decide  which  temperature 
is  the  best,  we  are,  through  experimental  evidence,  forced  to 
come  to  the  conclusion  that  a  ripening  temperature  between 
60°  and  70°  F.  gives  the  best  results. 

When  cream  is  ripened  at  a  high  temperature  it  needs  to  be 
cooled  very  little  previous  to  ripening.  Milk  is  usually  sepa- 
rated at  a  little  above  80°  F.,  and  if  the  starter  is  added  imme- 
diately after  separation,  it  will  ripen  in  a  very  short  time. 
If  ripened  at  a  lower  temperature,  a  longer  time  will  be  re- 
quired to  develop  the  same  amount  of  acid,  and  hence  with  a 
prolonged  ripening  period  more  attention  is  necessary.  The 
Danish  butter-makers  ripen  their  cream  at  a  comparatively 
low  temperature,  usually  between  60°  and  65°  F.,  and  obtain 
the  best  results. 

The  germs  producing  lactic  acid  grow  within  a  wide  range 
of  temperature;  viz.:  from  about  50°  to  100°  F.  The  extreme 
temperatures  are  not  favorable  to  the  greatest  possible  growth. 


CREAM  RIPENING. 


195 


The  optimum  temperature,  or  the  temperature  at  which  they 
grow  best  is,  according  to  Russell,  from  90°  to  95°  F.  At  this 
temperature  the  germs  which  cause  undesirable  results  also  grow 
most  rapidly  in  cream.  Cream  contains  germs  both  of  the 
desiarble  and  the  undesirable  type.  At  a  comparatively  low 
temperature  (between  60°  and  70°  F.)  the  greatest  relative 
growth  of  the  desirable  germs  is  produced.  Bacteriologists  also 


FIG.  128. — Cream-ripening  room  in  the  Model  Creamery  at  the 
World's  Exposition,  St.  Louis,  Mo. 

tell  us  that  the  casein  ferments  as  a  rule  thrive  better  at  a 
lower  temperature  than  do  the  lactic-acid  ferments  at  the  same 
temperature.  This,  keeping  in  mind  that  better  results  are 
obtained  by  ripening  at  lower  temperatures  (60°  to  70°  F.), 
seems  to  indicate  that  the  flavoring  substances  are  not  formed 
entirely  by  the  action  of  certain  germs  producing  lactic  acid, 
but  that  the  flavoring  substances  are  probably  due  to  the 
joint  action  of  several  species.  Lactic  acid  itself  does  not  have 


196  BUTTER-MAKING. 

the  desired  characteristic  flavor  of  good  butter,  yet  we  know 
that  these  flavoring  substances  are  direct  products,  or  accompani- 
ments, of  the  development  of  lactic  acid. 

Cream  ripened  at  a  low  temperature  does  not  sour  very 
rapidly;  the  germs  do  not  grow  at  a  very  rapid  rate.  The 
desired  degree  of  acidity  is  approached  very  slowly,  and  as  a  re- 
sult the  fermentation  may  be  checked  almost  at  once  when 
the  desired  degree  of  acidity  has  been  reached,  and  the  chance 
for  getting  overripened  cream  is  reduced  to  its  minimum. 
If  the  cream  is  ripened  at  a  high  temperature,  there  is  greater 
danger  of  getting  overripened  cream. 

Extreme  and  rapid  changes  of  temperature  should  be  avoided 
as  much  as  possible.  The  more  uniform  the  temperature  can 
be  kept,  if  suitable  for  proper  ripening,  the  better  the  results. 
Accordingly,  the  ripening-vats  used  in  this  country  are  practi- 
cally all  jacketed,  which  permits  the  operator  to  regulate  at 
will  the  temperature  of  the  water  in  the  jacket  surrounding  the 
cream. 

Amount  of  Starter  to  Add  to  Cream. — The  amount  of 
starter  to  add  to  cream  will  vary  according  to  the  temperature 
of  the  cream,  and  to  the  length  of  time  required  for  ripening. 
If  cream  is  to  be  ripened  quickly,  then  a  large  starter  should 
be  added.  Good  results  can  be  obtained  by  adding  starter  to 
the  extent  of  50%  of  the  cream  to  be  ripened.  This  much, 
however,  is  usually  not  satisfactory,  as  it  so  reduces  the  thick- 
ness of  the  cream  as  to  render  it  more  difficult  to  churn.  It 
increases  the  amount  of  serum  which  will  form  the  buttermilk 
when  churned.  The  more  buttermilk,  the  greater  will  be  the 
loss  of  fat  in  churning.  On  this  account  it  is  desirable  not  to 
add  any  more  starter  than  will  give  cream  a  proper  thickness 
(from  30%  to  35%  fat)  and  at  the  same  time  supply  enough 
desirable  germs  to  gain  the  upper  hand  of,  and  to  suppress  the 
undesirable  germs  already  present. 

It  is  important  to  skim  the  cream  thick  enough  to  permit 
the  use  of  an  amount  of  starter  equal  to  from  8%  to  20%  of 
the  cream  to  be  ripened.  This,  under  average  conditions,  will 


CREAM-RIPENING.  197 

produce  desirable  results,  providing  the  starter  is  of  the  proper 
kind.  A  poor  starter  is  worse  than  none  at  all. 

It  is  a  good  plan  to  pour  the  starter  into  the  ripening-vat 
before  the  cream  is  separated.  Some  also  practice  skimming  a 
heavy  cream  and  then  add  some  good  morning  milk  to  it. 

Before  the  starter  is  added  all  precautions  possible  should 
be  taken  in  order  to  prevent  the  entrance  of  undesirable  germs 
into  the  cream.  The  top  layer  of  the  starter  should  be  skimmed 
off;  and  the  very  bottom  portion  of  the  starter  should  not  be 
emptied  into  the  cream-vat  either,  as  it  usually  contains  some 
of  the  sediments  from  the  milk.  It  is  essential  that  the  starter 
should  be  thoroughly  stirred  previous  to  adding  it  to  the  cream, 
otherwise  lumps  of  curd  are  likely  to  trouble  during  the  re- 
mainder of  the  process  of  manufacture.  The  curd,  if  not 
properly  emulsified  previous  to  adding  it  to  the  cream,  is  likely 
to  show  itself  in  the  butter  in  the  form  of  white  specks.  This 
stirring  of  the  starter  can  be  brought  about  most  satisfactorily 
by  pouring  it  back  and  forth  from  one  can  into  another,  until 
the  body  of  the  starter  assumes  a  uniform,  not  lumpy,  con- 
sistency. The  cans  used  for  this  purpose  must  be  carefully 
cleaned  and  scalded  previous  to  using  them.  Dippers  and 
stirrers  of  any  kind  should  always  be  thoroughly  sterilized 
previous  to  using  them  in  starters.  The  stirrer  or  dipper  used 
should  have  solid  handles.  This  makes  cleaning  easier. 

Stirring  of  Cream  During  Ripening. — As  soon  as  the  starter 
has  been  brought  into  a  proper  condition  it  is  added  to  the 
cream.  If  necessary  it  should  be  strained  before  adding.  The 
cream  should  then  be  thoroughly  stirred.  If  cream  is  not 
thoroughly  mixed  with  the  starter,  the  ripening  will  not  be  uni- 
form. If  allowed  to  stand  quietly,  the  cream  soon  separates 
into  two  distinct  layers.  The  fat,  by  reason  of  its  being  lighter 
than  the  rest  of  the  constituents,  soon  forces  its  way  to  the 
surface,  and  incorporates  with  it  a  considerable  amount  of 
casein.  But  the  bottom  layer  will  be  similar  to  skim-milk; 
for,  being  better  mixed  with  the  starter,  the  lactic-acid  fer- 
mentation proceeds  more  rapidly  in  this  milky  or  bottom  layer, 


198  BUTTER-MAKING. 

and  thus  prevents  the  fat  which  is  at  the  surface  from  coming 
in  direct  contact  with  the  flavoring  substances  formed  at  the 
bottom.  If  the  surface  layer  of  fat  and  casein  were  exposed 
to  favorable  conditions,  the  point  might  be  made  that  the  sur- 
face exposure  is  more  desirable  than  if  the  fat  were  in  a  state 
of  perfect  emulsion  with  the  rest  of  the  constituents  of  cream. 
But  such  is  not  the  case.  The  layer  of  fat  and  curdled  casein, 
when  allowed  to  form  at  the  surface,  is  likely  to  be  contami- 
nated with  putrefactive  organisms.  Especially  is  this  so  if 
the  cream  is  allowed  to  stand  in  such  a  condition  very  long 
in  a  warm  ill- ventilated  room.  If  the  constituents  of  cream 
are  kept  well  mixed  by  stirring,  the  lactic  acid  checks  the 
development  of  putrefactive  germs,  which  may  accumulate  at 
the  surface;  the  cream  is  ripened  more  evenly,  and  the  flavor- 
ing substances  have  the  best  facilities  of  coming  in  contact 
with  and  being  absorbed  by  the  fat. 

The  authors  have  noticed  that  high-scoring  contest  butter 
is  usually  made  from  cream  which  has  been  stirred  judiciously 
at  intervals.  The  most  notable  prize  winners  have  stayed  up 
with  their  cream  all  night,  or  part  of  the  night,  to  watch  the 
ripening  process,  and  to  stir  the  cream  occasionally.  It  would 
not  be  practical  to  advise  this  method,  but  cream  should  re- 
ceive a  judicious  amount  of  stirring  at  intervals  during  the  day, 
and  if  it  is  allowed  to  stand  over  night,  it  should  be  stirred 
the  last  thing  in  the  evening  before  retiring. 

NATURAL  AND  ARTIFICIAL  RIPENING. 

Cream-ripening  as  a  whole,  as  practiced  to-day,  may  be 
divided  into  two  groups:  viz.,  (1)  Natural,  and  (2)  Artificial. 

Natural. — Natural  cream-ripening  consists  in  letting  the 
raw  cream  stand  at  a  certain  temperature  until  it  is  sour,  then 
cooling  it  to  the  churning  temperature.  This  method  used  to 
be  practiced  nearly  altogether,  but  now  experimental  and 
practical  evidence  prove  that  this  is  not  the  method  by  which 
the  best  butter  can  be  produced.  Natural  ripening  may,  or 


CREAM-RIPENING.  199 

may  not,  produce  good  results.  It  has  been  termed  by  some 
"chance  ripening."  At  certain  seasons  of  the  year  conditions 
are  favorable  for  natural  ripening,  while  at  other  seasons  con- 
ditions are  very  unfavorable.  It  was  stated  before  that  putre- 
factive organisms,  or  those  germs  causing  ordinary  decay,  are 
undesirable  species  of  bacteria  to  have  present  in  the  cream. 
During  the  late  spring  and  early  summer  months,  when  the 
cows  are  first  put  on  pasture,  the  conditions  are  favorable  for 
the  preponderance  of  the  desirable  germs;  during  the  winter, 
when  necessarily  the  cows  and  the  milk  are  subject  to  stable 
conditions  to  a  greater  extent,  the  conditions  are  favorable  for 
the  ascendency  of  the  undesirable  germs.  Eckles  has  found 
that  during  the  winter  about  three-fourths  of  the  bacteria  in 
milk  consists  of  these  undesirable  germs.  If  these  are  present 
in  the  milk,  a  proportionate  part  will  be  transferred  to  the 
cream.  When  such  cream  is  allowed  to  ripen  or  ferment  in  a 
natural  way,  the  undesirable  germs  are  likely  to  gain  the  ascen- 
dency. As  the  conditions  which  govern  the  degree  of  con- 
tamination of  the  milk  and  cream  vary  during  the  different 
days  of  the  different  months  and  different  seasons  of  the  year, 
this  natural  ripening  is  not  to  be  depended  on  for  obtaining 
a  good  uniform  quality  of  butter,  even  though  at  times  good 
results  may  be  obtained  from  natural  ripening.  A  maker  who 
wishes  to  make  a  high,  uniform  grade  of  butter  should  not 
depend  upon  natural  cream-ripening. 

Artificial  Ripening.  —  By  artificial  ripening  we  mean  (1) 
ripening  of  raw  cream  to  which  sufficient  starter  has  been 
added  to  control  the  kind  of  fermentation;  (2)  ripening  of  cream 
in  which  the  germs  have  been  destroyed  by  pasteurization, 
and  to  which  a  starter  has  been  added  in  order  to  introduce 
the  desirable  ferments. 

(1)  Either  of  these  methods  is  preferable  to  natural  cream- 
ripening.  The  first  method  has  been  the  most  common  in  the 
past,  but  the  latter  method  promises  to  give  results  which 
will  warrant  every  butter-maker  in  adopting  it  as  a  permanent 
method  in  butter-making.  If  cream  has  been  handled  under 


2(30  BUTTER-MAKING. 

conditions  which  are  favorable  for  the  introduction  of  desirable 
germs,  and  is  otherwise  in  good  condition,  the  best  results  can 
be  obtained  by  ripening  such  cream  without  pasteurizing  it. 
It  is  asserted  that  when  all  conditions  are  ideal, — the  starter 
good,  and  the  cream  good, — then  a  higher  flavored  butter  can 
be  produced  by  this  method  than  if  the  cream  were  pasteurized; 
but  the  keeping  quality  of  the  butter  is  not  so  good  as  that 
produced  from  pasteurized  cream.  The  same  objection  that 
was  made  to  natural  ripening  can  be  made  to  the  artificial 
ripening  of  raw  cream.  If  the  butter-maker  at  the  creamery 
has  full  control  of  all  the  conditions  governing  the  quality  of 
butter,  and  if  the  milk  is  received  at  the  creamery  in  an  ideal 
Condition,  then  this  method  of  ripening  is  commendable.  But 
at  creameries  where  milk  is  at  times  delivered  from  one  hundred 
or  more  different  patrons,  some  of  the  milk  is  likely  to  come 
in  in  an  unfavorable  condition.  The  poor  milk  is  likely  to 
contaminate  all  the  remainder  of  the  cream,  and  objectionable 
fermentative  products  are  likely  to  develop  in  the  cream-vat. 

When  this  method  of  ripening  is  practiced  the  starter  should 
be  added  to  the  cream  as  soon  as  possible.  In  fact,  this  rule 
applies  to  all  methods  of  cream-ripening  where  a  starter  is  used. 
It  is  preferable  to  add  the  starter  to  the  cream-vat  before  the 
skimming  is  begun.  In  this  way  the  lactic-acid  germs  in  the 
starter  get  a  chance  to  work  in  the  cream  immediately  after 
it  is  skimmed,  and,  for  this  reason,  are  more  likely  to  suppress 
the  undesirable  types  of  ferments  present. 

2.  The  second  method,  that  of  pasteurization,  is  without 
any  question  the  ideal  way  of  manufacturing  butter.  It  has 
been  advocated  in  a  theoretical  way  for  several  years  in  this 
country,  but  only  within  recent  years  has  this  method  of 
ripening  cream  been  deemed  sufficiently  meritorious  to  warrant 
its  adoption.  It  is,  however,  rapidly  gaining  in  favor.  The 
method  consists  in  heating  the  cream  on  a  continuous  pastuerizer 
from  155°  to  190°  F.  A  temperature  of  about  180°  F.  is  the 
one  usually  employed.  It  is  said  that  a  temperature  of  140° 
to  150°  F.  destroys  practically  all  the  germs  producing  lactic 


CREAM-RIPENING.  201 

acid.  Some  undesirable  germs  also,  in  a  vegetative  stage,  are 
not  destroyed  at  this  temperature.  For  this  reason  cream 
should  be  heated  to  about  180°  F.  At  this  temperature,  the 
germs  causing  tuberculosis  are  destroyed.  It  is  in  order  to  com- 
bat this  disease  that  the  Danish  Government  compels  all  cream 
to  be  pasteurized  before  it  is  made  into  butter,  and  also  all  of 
the  skim-milk  before  it  is  returned  to  the  farmer.  The  germs 
causing  tuberculosis  are  destroyed  at  a  lower  temperature  than 
this  (180°  F.),  provided  they  are  exposed  to  the  temperature  for 
some  time.  In  creameries  the  intermittent  method  of  pasteur- 
ization is  used.  In  this  method  the  time  of  exposure  to  the  heat 
is  short,  and  consequently  a  higher  temperature  is  necessary. 

By  heating  milk  to  such  a  temperature  practically  all  of  the 
germs,  desirable  and  undesirable,  are  destroyed  with  the  ex- 
ception of  those  that  are  present  in  the  spore  form.  If  this 
cream  is  inoculated  with  the  desirable  germs,  then  theoretically 
and  practically,  good  uniform  results  should  be  obtained. 

It  was  mentioned  above  that  the  spore-bearing  bacteria  were 
not  destroyed  by  the  degree  of  heating  to  which  cream  is  ex- 
posed. If  the  cream  is  allowed  to  stand  any  length  of  time  at 
a  favorable  temperature  without  a  starter  in  it,  these  spores 
will  develop  and  cause  undesirable  results.  If  pasteurized 
cream  is  allowed  to  ripen  naturally,  a  very  bitter  flavor  usually 
develops.  In  order  to  overcome  this  undesirable  fermentation, 
it  is  essential  that  the  starter  should  be  added  as  soon  as  possible 
after  the  cream  has  been  cooled  down  to  the  desirable  ripening 
temperature.  It  should  be  remembered  that  this  starter  should 
never  be  added  to  the  cream  while  it  is  still  hot,  as  the  lactic- 
acid-producing  germs  in  the  starter  would  then  be  destroyed. 

Ripening  Cream  When  Churning  is  Done  Once  Every  Other 
Day. — At  certain  seasons  of  the  year  the  milk  delivered  to  the 
creamery  is  not  sufficient  in  quantity  to  produce  enough  cream 
so  that  it  is  worth  while  to  churn  every  day.  Many  makers 
profitably  utilize  their  time  by  churning  only  every  other  day. 
The  question  then  comes,  how  may  the  cream  be  preserved  in 
the  best  possible  condition?  Some  prefer  to  cool  the  cream  to 


202  BUTTER-MAKING. 

a  low  temperature  (50°  F.)  immediately  after  it  has  been 
skimmed  or  received,  then  allowing  it  to  stand  until  the  next 
day.  The  second  day's  cream  is  then  poured  in  with  the  first 
day's  cream,  the  starter  added,  and  the  ripening  process  com- 
pleted. Others  prefer  to  add  the  starter  to  the  first  batch  of 
cream  immediately  after  it  has  been  skimmed,  then  ripen  it 
almost  to  the  normal  degree  of  acidity,  and  cool  to  about  50°  F. 
The  next  day  the  new  cream  is  skimmed  into  this  already 
ripe  cream,  stirred  thoroughly,  and  the  ripening  process  com- 
pleted. The  latter  method,  if  done  properly,  has  given  the  best 
satisfaction.  When  cream  is  ripened  according  to  the  method 
first  described,  undesirable  fermentations  are  likely  to  gain 
ascendency.  As  has  been  mentioned  before,  the  undesirable 
germs  grow  better  at  a  lower  temperature  than  do  the  bacteria 
producing  lactic  acid.  When  the  next  day's  cream  is  skimmed 
into  this,  the  undesirable  ferments  may  preponderate  to  such 
an  extent  that  the  desirable  germs  cannot  overcome  or  suppress 
them  during  the  remainder  of  the  ripening  process.  According 
to  the  latter  method,  the  first  day's  cream  is  ripened  as  usual. 
When  the  next  day's  cream  is  skimmed  into  this,  the  first  lot 
of  cream  acts  as  a  starter.  The  lactic  acid  present  inhibits 
the  growth  of  other  undesirable  species,  and  consequently 
better  results  are  obtained  by  this  method. 

This  latter  method  of  holding  cream  is  recommended  when 
cream  is  to  be  held  for  any  length  of  time,  such  as  over  Sunday, 
or  when  the  creamery  is  run  only  every  other  day,  and  the 
churning  done  once  or  twice  per  week.  If  possible,  and  all 
the  other  conditions  consistent,  it  is  better  to  ripen  the  cream 
and  churn  it  the  day  it  is  delivered  than  it  is  to  hold  the  cream 
over  for  several  days  before  it  is  churned.  Butter  will  always 
keep  better  than  cream,  under  any  conditions. 

MIXING  OF  CREAM. 

With  the  introduction  of  hand-separators  the  quality  of 
cream  received  at  creameries  varies  considerably.  The  ques- 
tion then  arises,  should  the  different  quantities  of  cream  be 


CREAM-RIPENING.  203 

mixed,  or  should  they  be  treated  separately  according  to 
quality,  and  made  up  into  several  grades  of  butter?  Theoret- 
ically the  grading  of  cream  into  two  or  three,  or  even  four, 
grades  can  be  argued  to  be  correct  and  proper,  yet  in  creameries 
where  only  a  comparatively  small  amount  of  cream  is  handled, 
it  usually  does  not  pay  to  grade  very  much.  In  a  very  large 
plant  where  as  much  as  50,000  pounds  of  butter  is  made  per 
day,  there  is  no  question  that  a  system  of  grading  cream  pays. 
Several  large  central  plants  are  now  grading  their  cream  into 
three  or  four  grades  successfully.  In  smaller  plants,  however, 
it  is  not  as  a  rule  advisable  to  make  more  than  two  grades, 
the  first  grade  to  include  all  good  and  fair  cream,  and  the 
second  grade  to  include  the  very  poorest.  Usually  in  the 
comparatively  small  creamery  plants,  the  quality  of  cream  can 
be  better  controlled,  and  consequently  less  grading  is  necessary, 
while  in  a  large  plant  the  creamery  manager  has  but  little  con- 
trol over  the  conditions  governing  the  quality  of  the  cream. 

The  chief  conditions  that  determine  whether  different 
qualities  of  cream  should  be  mixed,  might  be  said  to  depend 
upon: 

(1)  The  quality  of  the  cream. 

(2)  The  kind  of  market  for  the  butter. 

(3)  The  amount  of  hand-separator  cream  compared  with 

the  amount  of  good  quality  cream,  usually  sepa- 
rated from  the  milk  at  the  creamery. 

(4)  The  general  creamery  conditions. 

i.  Quality  of  Cream. — The  difficulty  of  grading  cream  is  met 
with  chiefly  in  comparatively  small  creameries  where  part  of 
the  intake  is  cream  and  another  part  milk.  The  cream  that 
is  separated  from  the  milk  at  the  factory  is  usually  in  an  ex- 
cellent condition,  while  the  cream  delivered  from  hand  sepa- 
rators, or  raised  by  any  of  the  gravity  methods,  is  usually  of  a 
poor  quality.  If  the  cream  delivered  to  the  creamery  is  in 
just  as  good  condition  as  that  obtained  from  wyhole  milk  skimmed 
at  the  factory,  then  there  is  no  danger  in  mixing  the  two  kinds 


204  BUTTER-MAKING. 

of  cream.  If  it  comes  in  a  poor  condition,  such  as  hand- 
separator  cream  usually  does,  then  the  poorest  cream  should 
be  ripened  by  itself.  Some  maintain  that  the  mixing  of  the 
two  kinds  of  cream  is  favorable,  because,  if  the  hand-separator 
cream  were  churned  separately,  it  would  produce  butter  which 
is  very  poor  in  quality,  while,  on  the  other  hand,  if  the  two 
were  mixed  a  better  quality  as  a  whole  would  be  obtained. 
This  is  undoubtedly  true;  but  evidently  if  the  quality  of 
butter  from  the  hand-separator  cream  was  raised,  that  from 
the  whole  milk  was  lowered,  so  that  the  quality  of  butter  re- 
ceived from  both  was  poorer  than  that  which  would  have  been 
obtained  from  the  whole  milk  if  kept  separate. 

2.  Kind    of  Market. — If  a   creamery   operator  is  working 
strictly  for  quality,  and  the  butter  is  sold  on  that  basis,  it 
certainly  would  not  be  a  good  plan  to  mix  the  poor  cream 
with  the  better  cream.     On  the  other  hand,  if  the  butter  is 
sold  on  the  market  with  no  attempt  to  establish  a  reputation, 
no  further  aim  than  to  get  as  much  as  possible  out  of  the  present 
supply,  then  it  might  pay.     By  mixing  the  two  it  might  be 
possible  to  raise  the  quality  so  as  to  bring  all  of  it  on  the  market 
at  a  trifle  above  "Creamery  Extras  ";  while  if  the  cream  from 
the  whole  milk  were  kept  separate,  perhaps  no  greater  price 
could  be  obtained  for  the  butter  produced  from  this  better 
cream.     If   the  butter  from   the   poor  hand-separator  cream 
were  placed  on  the  market  by  itself,  evidently  it  would  not 
command  the  same  price  as  that  made  from  the  whole  milk, 
or  the  mixed  lot  either.    As  has  been  stated  before,  the  mixing 
of  poor  cream  with  a  good  quality  of  milk,  skim-milk,  or  whole 
milk,  and  stirring  the  mixture  thoroughly  improves  the  quality 
of  the  butter  in  a  marked  degree. 

3.  Amount   of   Cream. — If  only  a  small  amount  of  hand- 
separator  cream  is  being  received,  then  usually  it  will  not  pay 
to  carry  it  through  by  itself.     By  experience  the  authors  have 
found  that  the  best  way  to  dispose  of  a  comparatively  small 
amount,  providing  it  is  not  too  sour,  is  to   empty  it  into  a 
receiving-vat  with  the  milk,  and  stir  it  well,  re-skim  it  and 


CREAM-RIPENING.  205 

pasteurize  all  the  cream,  add  a  starter,  and  ripen  in  the  usua 
way.  If  the  cream  is  sour,  and  there  is  a  danger  of  souring 
the  remainder  of  the  milk,  or  clogging  the  separator,  it  is  ad- 
visable to  add  it  directly  to  the  cream-vat.  The  sourness  of 
the  cream  is  not  so  dangerous  if  the  flavor  is  clean.  If  it  is 
very  unclean,  and  not  sour,  the  mixing  with  the  whole  milk, 
the  separation,  and  pasteurization  will  eliminate  a  great  many 
of  the  undesirable  flavors  and  check  the  activity  of  a  large 
portion  of  the  undesirable  germs  present.  When  the  starter 
is  again  added  and  ripened,  a  good  quality  of  butter  is  ob- 
tained. If  a  comparatively  large  amount  of  cream  in  poor 
condition  is  received,  then  it  is  advisable  to  retain  it  by  itself. 

4.  General  Creamery  Conditions. — Occasionally  it  happens 
that  a  creamery  is  not  properly  equipped  with  vats,  so  as  to 
enable  an  operator  to  handle  two  lots  of  cream.  Where  one 
man  has  to  do  all  the  work,  one  churning  is  about  all  he  can 
accomplish  daily,  besides  attending  to  the  remainder  of  the 
work.  Under  such  conditions  it  is  doubtful  whether  it  will 
pay  to  purchase  additional  vats  and  hire  additional  help,  in 
order  to  keep  poor  hand-separator  cream  separate  from  the 
remainder,  through  the  different  steps  of  manufacture.  Since 
the  butter  is  not  sold  strictly  on  its  merits,  there  would,  as  a 
rule,  be  no  profit  for  the  average  small  creamery  to  grade  the 
cream,  on  account  of  the  additional  labor  and  apparatus  re- 
quired. If  a  high  quality  of  butter  is  the  supreme  aim  of  the 
creamery  operator,  then  it  becomes  very  essential  that  the  poor 
cream  be  kept  separate. 

EXAMINING  AND  TESTING  CREAM  FOR  ACIDITY  DURING 
RIPENING. 

As  has  been  stated  before,  the  best  flavor  in  butter  is  pro- 
duced when  cream  is  ripened  to  the  proper  degree  of  acidity. 
If  it  is  ripened  too  much,  or  overripened,  the  butter  will  assume 
a  high  flavor  and  strong  aroma,  while  if  not  ripened  high  enough, 
it  will  be  a  little  flattish  with  less  aroma.  Many  makers  depend 


206 


BUTTER-MAKING. 


upon  the  taste  and  smell,  and  the  appearance  of  the  cream, 
to  decide  when  the  cream  has  been  ripened  to  the  desired 
degree  of  acidity.  Makers  with  a  great  deal  of  experience  are 
able  to  tell  quite  accurately  by  the  appearance  of  the  cream 
and  its  taste  and  smell  when  it  has  been  properly  ripened. 
Well-ripened  cream  gets  an  apparently  granular  and  glistening 
condition.  It  has  a  pleasant,  mild  acid  taste,  and  a  good 
clean  sourish  aroma. 

As  the  flavor  of  properly  ripened  cream  will  vary  somewhat 
according  to  the  different  degrees  of  richness  of  the  cream,  it 
is  very  easy  to  be  deceived  by  the 
senses.  For  this  reason  it  is  advisable 
to  use  a  special  test  with  which  to 
measure  the  amount  of  acid  developed 
in  the  cream.  There  are  two  acid  tests 
in  general  use  now  in  creameries,  viz., 
" Mann's  Test"  and  the  "Farrington 
Test.". 

Mann's  Test. — Mann's  test  consists 
of  measuring  the  acid  in  the  cream 
i  by  means  of  an  alkali  of  a  definite 
known  strength.  The  kind  of  alkali 
used  is  usually  a  .1  normal  solution  of 
caustic  potash  (KOH)  or  soda  (Na.OH). 

FIG.   129.— Apparatus    for  rrn          solutions  ran   be  made  im   vprv 
Mann's    acid    test.      In-    J 

stead  of  the  burette  the  cheaply    or   bought   from  the   supply- 
alkali  can  be  kept  in  a   ,  ...        .  .    ,          , 
large  bottle,  as  shown  in  houses.     Mann  s  test  is  based  upon  mea- 

Fig.  131  and  130.  suring   out  50  c.c.  of  cream  by  means 

of  a  pipette.  A  few  drops  of  an  indicator  (phenolphthalein) 
is  added.  This  indicator  gives  a  red  color  in  an  alkaline  solu- 
tion, and  no  color  in  an  acid  solution.  The  .1  normal  alkali 
is  poured  into  a  burette,  and  the  solution  allowed  to  run  into 
the  50  c.c.  of  cream  and  stirred  thoroughly  until  it  begins  to 
turn  pink  in  color.  At  this  point  it  is  neutral.  The  number 
of  cubic  centimeters  of  alkali  required  to  neutralize  the  acid 
in  50  c.c.  of  cream  indicates  the  number  of  degrees  of  -acid. 


CREA  M -RIPEN  ING. 


207 


For  instance,  if  it  required  32  c.c.  of  a  tenth  normal  alkali 
to  neutralize  the  acid  in  50  c.c.  of  cream,  the  acidity  of  the 
cream  would  be  32°. 

(1  c.c.  of  N/10  alkali  =  1°  Mann's  Test.) 

Mann's  test  reading  can  be  converted  so  as  to  express  the 
results  in  percentage  similar  to  the  Farrington  test.    As  1  c.c. 


FIG.  130.— Arrangement 
for  keeping  alkali  for 
the  Mann's  test. 


FIG.  131. 


of  the  .1  normal  alkali  neutralizes  .009  grams  of  pure  lactic 
acid,  32  c.c.,  as  in  the  above  case,  would  neutralize  32  times  .009. 
This  would  give  the  amount  of  acid,  calculated  in  terms  of 
lactic  acid,  present  in  the  50  c.c.  of  cream.  This  product 


208 


BUTTER-MAKING. 


divided  by  the  50,  and  multiplied  by  100,  would  give  the  per- 
centage of  the  acid  present. 

Farrington  Test. — The  same  principle  is  involved  in  the 
P'arrington  test.  The  alkali  is  put  up  in  small  tablets,  already 
containing  the  indicator.  These  tablets  contain  a  definite 
amount  of  alkali,  and  are  represented  as  retaining  their  strength. 
However,  they  lose  their  strength  if  they  are  exposed  to  the 
atmosphere.  The  amount  of  alkali  embodied  in  each  tablet  is 
such  that  when  five  of  them  are  taken  into  a  graduated  cylin- 
der, the  cylinder  filled  up  with  distilled  water  to  the  97-c.c. 


FIG.  132. — Apparatus  for  the  Farrington  acid  test. 

mark,  and  the  tablets  thoroughly  dissolved  in  water,  a  solution 
is  obtained,  each  cubic  centimeter  of  which  represents  .01  of 
1%  of  acid,  providing  17.6  c.c.  of  cream  is  taken.  The  tablets 
can  be  made  up  of  different  strengths  for  the  use  of  different- 
sized  pipettes,  but  as  the  17.6-c.c.  pipette  is  the  one  which  is 
used  in  the  ordinary  Babcock  test,  directions  are  given  for  the 
use  of  that  pipette  only.  For  a  more  detailed  description  of 
the  acid  tests  see  "Milk  Testing,"  by  Farrington  and  Woll. 

Amount  of  Acid  to  Develop. — The  amount  of  acid  to  develop 
in  cream  depends  upon  the  amount  of  fat  present  in  the  cream, 
and  to  some  extent  upon  the  market  on  which  the  butter  is 


CREAM-RIPENING.  209 

to  be  sold.  Some  markets  require  higher  flavored  butter  than 
others.  Practically  all  markets,  especially  in  this  country, 
demand  butter  which  has  a  comparatively  rich  creamy  flavor, 
with  a  nice  clean  butter  aroma. 

It  was  found  at  the  Iowa  Experiment  Station,  from  a  large 
number  of  experiments,  that  cream  containing  30%  fat  gave 
the  best  results,  that  is,  showed  the  highest  flavor  when  ripened 
to  37  degrees,  Mann's  test.  It  has  also  been  demonstrated  that 
acid  is  developed  only  in  the  serum  portion  of  the  cream.  This 
would  bring  the  cream-ripening  process  down  to  a  question  of 
proportion,  as  the  fat  is  practically  neutral.  By  subtracting  the 
30%  fat  we  have  70%  serum.  This  would  equal  .53  degree 
of  acid  to  each  per  cent  of  serum.  Thus,  70%  serum  multiplied 
by  .53  would  give  us  37.1  degrees,  Mann's  test.  For  instance, 
if  we  take  40%  fat,  we  would  have  60%  serum,  and  this 
multiplied  by  .53  would  give  us  31.8  degrees  to  ripen  to.  With 
thin  cream  of  20%  we  would  have  80%  serum,  which  would 
equal  42.4  degrees  to  ripen  to. 

We  would  not  recommend  following  the  above  formula  to 
tne  extreme  with  thin  cream.  For  20%  cream  42  degrees 
would  be  sufficiently  high  to  ripen  to,  even  with  exception- 
ally good  cream.  When  the  flavor  of  the  cream  is  not 
good  it  is  not  desirable  to  ripen  to  quite  as  high  a  degree  of 
acidity. 

Another  formula  which  has  worked  very  satisfactorily  in  the 
Dairy  Department  at  Iowa  State  College,  and  which  does  not 
give  as  high  a  degree  of  acidity,  is  as  follows:  Subtract  the 
per  cent  of  fat  found  in  cream  and  divide  the  serum  by  two^ 
and  the  quotient  will  be  the  degree  to  ripen  to.  For  instance, 
30%  cream  giving  70%  serum  would  give  35  degrees  to 
ripen  to. 


210  BUTTER-MAKING. 


CHEMICAL,  PHYSICAL,  AND  BIOLOGICAL  CHANGES. 

Physical  Changes. — All  the  changes  in  cream  during  ripening 
are  very  complex,  and  the  causes  of  them  are  not  well  under- 
stood. The  chief  cause  of  the  ripening  process,  as  it  normally 
occurs,  is  the  action  of  micro-organisms.  As  has  been  stated 
before,  the  germs  producing  lactic  acid  are  the  most  numerous. 
These  germs  continue  to  gain  the .  ascendency  in  the  cream 
during  the  ripening  until  cream  is  almost  a  pure  culture  of 
lactic-acid-producing  germs.  Accompanying  this  growth,  the 
sugar  present  in  the  cream  is  broken  up  into  lactic  acid  and 
several  other  by-products  which  will  be  mentioned  later. 

These  different  by-products  have  certain  physical  effects 
upon  the  body  of  the  cream.  The  acid  developed  causes 
the  cream  to  coagulate  and  become  thick.  As  the  ripening 
process  is  carried  on  the  appearance  of  the  cream  changes  some- 
what. It  becomes  thick,  granular,  and  glistening  in  appear- 
ance. Undoubtedly  the  film  of  casein,  or  whatever  the  envelop- 
ment may  be,  surrounding  the  fat-globules,  is  loosened  or  cut. 

Biological  Changes. — Cream  when  put  into  the  ripening-vat 
usually  contains  a  very  large  variety  of  bacteria.  Which 
species  predominates  at  that  time  depends  upon  the  care  and 
treatment  of  the  cream  previous  to  the  ripening  stage.  In 
pasteurized  cream  practically  all  the  germs  present  are  of  the 
spore-producing  kind,  and  unless  conditions  are  favorable  for 
the  development  of  the  spores,  these  will  be  suppressed  by  the 
germs  added  with  the  starter.  During  the  first  few  hours  of 
the  ripening  process  there  is  a  gradual  growth  of  all  the  germs 
present.  It  is  said  that  in  sweet  cream  the  lactic  acid  germs 
are  comparatively  few  in  number,  but  under  favorable  conditions 
these  grow  so  much  more  rapidly  in  number  than  any  of  the 
others,  that  in  a  short  time  they  become  more  numerous  than 
all  the  other  germs.  The  by-product  lactic  acid  is  unfavorable 
for  the  growth  of  nearly  all  the  undesirable  varieties  of  germs. 
Practically  all  these  germs  are  suppressed  in  their  development, 


CREAM-RIPENING 


211 


so  that  when  cream  is  ripened  properly,  it  contains  few  other 
germs  besides  those  which  produce  lactic  acid. 

From  the  above  it  will  be  seen  that  there  are  practically  two 
overlapping  periods  in  the  bacterial  changes  during  the  ripening 
of  the  cream,  and  especially  is  this  so  in  the  ripening  of  raw 
cream.  The  first  includes  the  period  when  all  the  different 
varieties  of  germs  grow,  and  the  second  includes  the  period 
when  only  the  lactic-acid-producing  germs  grow.  It  is,  there- 
fore, maintained  that  before  the  churning  takes  place  the 
ripening  of  cream  should  be  carried  on  to  such  an  extent  that 
the  lactic-acid  germs  only  predominate.  Dr.  Storch,  who  has 
made  a  detailed  study  of  this,  asserts  that  milk  and  cream 
both  have  a  rather  undesirable  flavor  at  the  beginning  of  its 
ripening  period,  while  in  the  latter  stage  of  the  ripening  period 
it  takes  on  a  pleasant,  clean,  acid  taste. 

The  number  of  germs,  and  the  relative  number  of  acid-pro- 
ducing germs  in  the  cream  when  ripened,  is  as  shown  in  the 
following  table :  * 


Date. 

Quality  of 
Cream. 

Number  per  c.c. 

Number  Acid 
per  c.c. 

Per 

Cent 
Acid. 

Number  Non- 
acid  per  c.c. 

Per 
Cent 

Non- 
acid. 

Feb.   11 

Fine 

280,000,000 

257,000,000 

92 

22,400,000 

8 

Jul.     18 

Poor 

19 

"       30 

Excellent 

3,002,000,000 

2,851,190,000 

95 

150,810,000 

5 

Aug.  11 

Good 

1,107,000,000 

1,012,072,200 

91.5 

94,928,800 

8.5 

Sep.      3 

Fair 

1,027,000,000 

955,110,000 

93 

71.890.000 

7 

5 

Good 

2,007.958,000 

1,827,370,000 

91 

180,588,000 

9 

Oct.    28 

" 

392,958,000 

385,098,840 

98 

7,859,160 

2 

"      30 

393,700,000 

381,889,000 

97 

11,811,000 

3 

Eckles  found  that  when  good- flavored  cream  is  ready  for 
churning  the  number  of  bacteria  per  cubic  centimeter  varies 
from  380,000,000  to  3,000,000,000.  Of  this  number  the  acid- 
producing  bacteria  constitute  from  91%  to  98%. 

Chemical  Changes. — The  changes  in  cream  during  the  process 


*  Bui.  40,  Iowa  Experiment  Station. 


212  BUTTER-MAKING. 

of  ripening  are  not  due  to  any  instability  of  the  components 
of  cream,  nor  are  they  attributed  to  any  of  the  enzymes. 
Galactase  is  a  pre-existing  enzyme  in  milk;  consequently  it 
would  be  present  in  cream,  but  present  only  to  a  very  small 
extent.  If  it  were  possible  to  exclude  from  the  cream  all  the 
different  kinds  of  bacteria,  ripening  would  not  take  place. 
At  least  it  would  proceed  at  a  much  slower  rate  than  the 
ordinary  rate  of  change  in  the  ripening  of  cream  ;  this  proves 
that  the  solids  of  cream  are  chemically  stable  and  that  the 
enzymes  or  unorganized  ferments  play  only  a  secondary  part 
in  bringing  about  the  different  changes  in  cream  ripening. 
There  are  two  classes  of  solids  in  cream  which  are  decom- 
posed chiefly  during  ripening :  viz.,  (1)  Albuminoids,  and  (2) 
Sugar. 

1.  Most  authorities  maintain  that  bacteria  are  unable  to 
feed  on,  or  to  decompose  directly  any  substance  which  is  not 
present  in  the  form  of  a  solution.  As  casein  is  not  normally 
present  in  a  solution  in  milk,  the  pre-existing  enzymes  or 
bacterial  by-products  must  cause  the  first  decomposition  of 
casein  before  the  germs  are  able  to  utilize  it.  The  by-products 
resulting  from  the  casein  ferments  are  many,  and  very  com- 
plex. According  to  Russell  *  albumoses,  leucin,  peptone, 
ty rosin,  and  ammonia  are  formed.  Freudenrich  claims  that  in 
addition  to  these  butyric  acid  is  a  by-product.  Besides  these 
substances,  gases  such  as  carbonic  gas,  marsh-gas,  and  nitrogen 
are  formed.  Whether  all  these  by-products  are  formed  directly 
or  indirectly  or  both,  no  one  knows  for  certain. 

The  typical  ferments  seem  to  act  similarly  upon  the  casein 
in  milk.  They  produce  first  a  rennet-like  fennent,  which 
curdles  the  milk.  After  it  has  been  curdled,  the  curd  is  digested 
or  peptonized  by  the  action  of  some  enzyme.  The  casein  in  a 
sample  of  milk  containing  a  preponderance  of  casein  ferments 
will  in  a  few  weeks,  or  even  less  time,  disappear  entirely.  Ap- 
parently the  milk  has  been  transformed  into  whey.  This 
particular  ferment  is  called  casease  by  Duclaux.  Conn  calls 

*  Dairy  Bacteriology. 


CREAM-RIPENING.  213 

it  a  tryptic  ferment,  because  it  is  similar  in  its  action  to  the 
trypsin  produced  by  the  digesting  glands.  The  putrefactive 
germs  ordinarily  act  upon  the  nitrogenous  matter  of  cream, 
as  described  above. 

2.  The  milk-sugar  in  cream  is  present  in  a  perfect  solution, 
and  consequently  it  is  thought  that  bacteria  are  able  to  utilize 
it  as  food  directly.  The  typical  lactic-acid-producing  germs 
cause  the  milk-sugar  to  split  up  into  lactic'  acid  chiefly,  accord- 
ing to  the  following  equation: 


Milk-sugar.  Lactic  acid. 

There  are  a  number  of  germs  which  are  able  to  produce 
lactic  acid  from  milk-sugar,  but  practically  all  of  them,  so  far 
as  known,  produce  other  by-products  besides  the  lactic  acid. 
Some  germs  produce  much  lactic  acid  and  a  small  amount  of 
other  by-products,  while  other  germs  produce  little  lactic  acid 
and  large  amounts  of  several  other  by-products.  Some  of  them 
break  up  the  milk-sugar  and  change  it  into  lactic  acid  and  car- 
bonic gas.  Other  species  produce  lactic  acid  and  alcohol. 
This  latter  species  Grottenfelt  claims  to  be  closely  associated 
with  the  production  of  flavoring  substances  in  butter.  Different 
kinds  of  gases,  such  as  nitrogen,  hydrogen,  carbonic-acid  gas, 
and  marsh-gas  are  also  formed. 

It  is  doubtful  whether  there  are  any  germs  which  are  able 
to  transform  milk-sugar  entirely  into  lactic  acid.  If  such  were 
the  case,  1  gram  of  milk-sugar  would  produce  1  gram  of  lactic 
acid.  According  *  to  some  experiments  carried  on  by  one  of 
the  authors,  .8  of  a  gram  was  the  maximum  amount  of  acid 
developed  from  1  gram  of  milk-sugar,  and  .5%  is  the  average 
amount  of  acid  developed  from  1  gram  of  milk-sugar.  In  the 
experiments,  efforts  were  made  to  have  the  typical  lac  tic-  acid 
ferments  present  in  the  cream.  The  following  table  may  prove 
of  some  interest  : 

*  Chemical  Changes  during  Cream  Ripening.     (Thesis  I.  S.  C.) 


214  BUTTER-MAKING. 

CREAM  I. 

Sugar.  Acid.  ^  S^L 

1st  ripening  period 1%  produced  .04%  .33% 

2d         "  '•'     1  "  .06  .35 

CREAM  II. 

1st  ripening  period 1%  produced  .08%  .58% 

2d         "  "     1  "  .06  .64 

3d         "  "     1  "  .045  .82 

CREAM  III. 

1st  ripening  period 1%  produced  .051%  -58% 

2d         "  "     1  "  .050  .63 

3d         "  "     1  "  .016  .68 

Average  of  Siexperiments 1  "  .05  + 

Conn  states  that  the  lactic  acid  produced  in  cream  during 
ripening  is  not  always  of  the  same  kind.  Some  species  of 
bacteria  produce  the  kind  which  turns  the  plane  of  polarization 
to  the  left;  other  species  produce  the  kind  which  turn  it  to 
the  right,  and  still  other  species  produce  the  so-called  inactive 
lactic  acid.  The  most  common  are  those  which  produce  acid 
that  turns  the  plane  of  polarization  to  the  right. 

The  souring  of  cream,  according  to  Conn,  is  not  due  to  the 
development  of  lactic  acid  alone.  Two  kinds  are  produced, 
(1)  fixed,  and  (2)  volatile.  The  fixed  acids  appear  to  be  chiefly, 
if  not  wholly,  lactic  acid,  and  the  volatile  are  chiefly  acetic  and 
formic  acids.  The  fixed  acids  are  produced  in  the  greatest 
proportion. 

In  the  table  quoted  above,  it  will  be  seen  that  during  the 
first  ripening  period  of  sample  3,  .1%  sugar  produced  .051%  of 
acid,  while  during  the  last  or  third  ripening  stage  .1%  of  sugar 
produced  .016%  of  acid,  being  only  about  one- third  of  that 
produced  during  the  first  ripening  period.  The  same  is  true 
in  experiment  II,  where  three  separate  analyses  were  made  of 
the  cream.  It  is  difficult  to  account  for  the  constant  decrease 
of  lactic  acid  in  proportion  to  the  sugar  decomposed  in  the 
advanced  stage  of  the  ripening  period.  Is  it  the  lactic  acid 
already  present  that  decomposes  into  other  products  when  so 
much  acid  is  formed?  Or  do  the  bacteria  continue  to  decom- 
pose the  sugar,  but  the  by-products  being  of  a  different  nature? 


CREAM-RIPENING.  215 

Or  do  certain  species  of  bacteria  cease  to  act,  and  are  other 
species,  which  produce  less  lactic  acid  and  more  gaseous  prod- 
ucts, able  to  perpetuate  their  growth  and  bring  about  the 
results  observed?  The  results  are  probably  due  to  a  com- 
bination of  the  different  actions  just  mentioned,  but  the  most 
likely  theory  is  that  conditions  for  the  growth  of  other  species 
of  bacteria  become  more  favorable,  and  other  by-products 
than  lactic  acid  are  formed,  products  that  cause  the  undesirable 
rancid  flavors  in  over-ripened  cream. 

Butyric  acid  also  results  from  the  decomposition  of  cream 
constituents  during  ripening.  The  origin  of  the  butyric  acid 
formed  during  ripening  is,  however,  not  well  known.  Freuden- 
reich  says  it  is  the  residue  resulting  from  the  breaking  down  of 
casein  and  milk-sugar  in  various  ways,  and  therefore  he  classes 
the  butyric  ferments  in  the  same  group  as  the  casein  ferments. 

Butyric  acid  in  overripened  cream  is  by  some  authorities 
considered  to  be  a  direct  product  from  an  excessive  amount  of 
lactic  acid.  Each  molecule  of  lactic  acid  breaks  up  into  butyric 
acid,  carbonic-acid  gas,  and  hydrogen,  according  to  the  follow- 
ing equation: 


Lactic  acid.  Butyric  acid.  id^as"      Hydr°gen. 

2C3H603    =    C3H7C02H     +     2C02     +     H4. 

It  is  questionable  whether  this  reaction  ever  occurs  in  the 
ripening  of  cream. 

Butyric  acid  also  results  from  the  decomposition  of  butyrin, 
through  the  action  of  bacteria,  and  causes  the  molecules  of  fat 
to  split  up  into  butyric  acid  and  glycerine,  according  to  the 
following  equation  : 

Butyrin  (fat).  Water.  Glycerine.  Butyric  acid. 

f  C3H7C02  f  OH 

C3H5  j  C3H7C02     +     3H20     =     C3H5  j  OH    +   3C3H7C02H 
1C3H7C02  [OH 


CHAPTER  XV. 

STARTERS. 

Definition. — By  the  term  starter,  in  cream-ripening,  we 
understand  a  medium  containing  a  preponderance  of  desirable 
germs  present  in  a  virulent  condition. 

History. — -The  use  of  starters  in  the  dairy  industry  dates 
back  a  great  many  years.  The  fact  that  starters  helped  in  the 
manufacture  of  dairy  products  was  recognized  years  ago  by 
practical  men  even  before  scientists  recommended  the  use  of 
pure  cultures.  In  European  dairy  countries  the  use  of  the 
buttermilk  borrowed  from  a  neighboring  factory  to  add  to  the 
cream  in  order  to  overcome  abnormal  conditions,  was  a  common 
occurrence.  In  Holland,  sour  whey  borrowed  from  some  other 
factory  was  used  to  overcome  gassy  fermentation  in  cheese- 
making.  While  the  reasons  for  this  were  not  well  understood, 
the  underlying  principle  was  involved,  viz.,  that  of  overcoming 
the  undesirable  fermentation  by  adding  ferments  of  an  an- 
tagonistic kind. 

The  introduction  of  pure  cultures,  or  commercial  starters, 
for  cream-ripening  dates  back  to  1890,  by  Professor  S torch. 
He  recommended  their  use  in  creameries  in  Denmark.  Starters 
were  used  in  that  country  for  a  time  successfully,  and  since 
then  starters  have  been  introduced  and  extensively  used  in 
this  country,  as  well  as  in  practically  all  European  countries. 

Classification  of  Starters. — Generally  speaking,  the  different 
kinds  of  starters  are  included  under  the  names  (1),  Natural, 
and  (2)  Commercial.  The  latter  is  prepared  from  a  pure 
culture  of  bacteria  obtained  from  the  laboratory.  The  former, 
or  natural,  include  a  great  many  kinds  of  dairy  products  which 

216 


STARTERS.  217 

are  supposed  to  contain  a  preponderance  of  those  germs  which 
are  involved  in  the  production  of  desirable  flavors  in  butter. 
Buttermilk,  sour  cream,  whey,  and  sour  whole  or  skim-milk, 
are  classed  under  this  heading.  While  all  these  may  be  termed 
natural  starters,  and  at  certain  times  the  use  of  any  one  of 
them  may  produce  better  results  than  if  no  starter  at  all  were 
used,  it  is  not  safe  to  rely  upon  these  to  bring  about  better 
results  than  could  be  obtained  without  the  use  of  starters, 
because  these  products  are  likely  to  be  contaminated  in  a  large 
degree  with  undesirable  germs. 

Preparation  of  Natural  Starters. — The  best  natural  starter 
is  usually  obtained  by  selecting  a  number  of  different  samples 
of  the  best  milk  coming  into  the  creamery,  into  cleaned  sterile 
glass  jars.  The  samples  are  allowed  to  stand  until  sour  at 
about  70°  F.  The  sample  which  coagulates  into  a  smooth  uni- 
form curd,  and  has  a  pleasant  acid  taste  and  smell  is  selected 
and  used  as  a  mother-starter.  When  inoculated  into  a  large 
quantity  of  selected  pasteurized  skim-milk,  cooled  to  and  kept 
at  a  temperature  of  about  70°  F.  until  it  begins  to  coagulate, 
it  will  usually  produce  a  starter  which  is  equal,  and  often 
superior,  to  a  commercial  starter. 

Commercial  Starters,  or  Pure  Cultures. — Experiments  have 
amply  proved  that  certain  species  of  bacteria  are  chiefly  re- 
sponsible for  the  butter  flavors  developed  in  cream  during 
ripening.  This  fact  has  given  rise  to  the  use  of  pure  cultures 
prepared  in  a  commercial  way.  These  pure  cultures  contain, 
in  a  virulent  condition,  the  germs  which  produce  the  desirable 
flavors  and  aroma.  The  cultures  are  put  up  in  laboratories 
specially  provided  for  this  kind  of  work.  The  germs  are  iso- 
lated and  inoculated  into  a  medium  which  is  suitable  to  their 
growth.  Some  laboratories  inoculate  them  into  a  liquid  medium, 
others  into  a  powder  medium.  The  liquid  medium  consists 
usually  of  sterilized  bouillon,  or  milk.  The  powder  medium 
consists  chiefly  of  milk-sugar.  The  cultures  that  are  put  up 
in  the  liquid  form  will  not  keep  so  long,  and  it  is  not  safe  to  use 
them  after  they  are  about  nine  days  old.  The  cultures  which 


218 


BUTTER-MAKING. 


are  put  up  in  powder  form  have  the  advantage  that  they  can 
be  kept  for  a  much  longer  time  and  still  retain  their  vitality. 
Both  kinds  as  a  rule  are  good  while  they  are  fresh.  We  give 
below  a  list  of  the  commercial  cultures  with  which  the  authors 
are  familiar: 


S.  C.  Keith, 
Charlestown, 
Mass. 

1  Lactic  Acid  Culture.      ") 
\  Duplex  Culture               \  Liquid. 
j  Boston  Butter  Culture  J 

O.  Douglas, 
Boston, 
Mass. 

")  Boston  Butter  Culture  ] 
\  Duplex  Culture                [  Liquid. 
J  Lactic  Acid  Culture 

Ameri- 

Eloc Ericsson, 
St.  Paul, 
Minn. 

Ericsson's  Butter  Cul-  J  T  .      .  , 
}      ture                                j  Liquid. 

can 

Hansen's, 

1 

Little  Falls, 

\  Lactic  Ferment                  Powder. 

N..Y. 

J 

Commer- 
cial 
Starters 

Park  Davis  &  Co.  , 
Detroit, 
Mich. 

1                      I"  This  culture  is  put  up 
\  Flavorone  \      in  tablet  and  cap- 
[_      sule  forms. 

Conn's  Culture, 
Storr  Station, 
Conn. 

1 
|-  Bacillus  41                           Liquid. 

'  Blauenfeldt  & 
Tvede,  Copen- 
hagen, Den. 

Danish  Lactic  Acid 
j      Ferment 

Foreign 

Hjort  &  Fog's 
Lab'tory    Cul. 
Copenhagen, 
Den. 

] 
f  Lactic. 

J 

S.  P.  Storm, 
Tillitze,  Naks- 

1 
[  Starter. 

kov,  Den. 

J 

Preparation  of  Commercial  Starters. — All  of  the  starters 
mentioned  above  have  been  tested  and  are  known  to  produce 
good  results.  The  first  step  in  the  preparation  of  a  mother- 
starter  (starterline)  is  to  prepare  preferably  a  glass  jar  or 
bottle  by  thoroughly  cleaning  and  sterilizing  it.  Glass  jars  are 
used  in  preference  to  any  other  vessel,  because  if  they  are  un- 
clean in  any  way,  it  will  show  through  the  glass.  Secondly, 
there  are  no  seams  and  no  places  on  the  inside  which  will  cor- 


STARTERS.  219 

rode,  and  in  that  way  retain  unnoticeable  dirt.  Mason  jars 
and  sampling  bottles  are  suitable.  The  kind  of  bottle  which 
is  used  for  marketing  milk  gives  very  good  results. 

The  second  step  consists  in  selecting  suitable  milk.  The 
milk  must  be  in  as  pure  and  sweet  a  condition  as  possible.  A 
good  starter  can  be  produced  from  either  whole  or  skim-milk. 
Skim-milk,  however,  is  preferable  to  whole  milk.  The  mis- 
take of  selecting  whole  milk  for  starters  has  often  been  made. 
The  mother-starter  prepared  from  whole  milk  usually  has  a 
more  pleasant,  mild,  rich  taste,  due  to  the  fact  that  it  contains 
more  fat  than  the  starter  made  from  skim-milk.  The  mother 
starter  prepared  from  good  skim-milk  is  preferable,  and  safer 
to  rely  upon.  Efforts  should  be  made  towards  separating  the 
starter  milk  before  the  rest  of  the  milk  has  been  run  through. 
If  not  separated  till  late  during  the  run  of  the  day,  the  separator 
is  filled  with  slime  and  bowl-slush,  which  are  likely  to  con- 
taminate the  starter  milk.  At  some  creameries,  the  separation 
of  the  starter  milk  is  accomplished  with  a  small  hand  sepa- 
rator. This,  however,  is  not  convenient  or  practicable  at  most 
creameries.  The  milk  for  the  starter  can  be  selected  and  run 
through  the  power  separator  during  the  beginning  of  the  run. 
It  is  well  not  to  use  the  very  first  milk  which  passes  through 
the  separator,  as  it  would  be  likely  to  contain  a  greater  number 
of  undesirable  germs. 

The  milk  which  has  been  selected  for  the  mother-starter, 
or  starterline,  is  then  pasteurized.  The  pasteurization  is  best 
accomplished  by  the  intermittent  method.  If  considerable 
milk  is  to  be  pasteurized  it  is  best  to  make  use  of  a  clean, 
sterilized  can.  If  only  a  small  portion  is  to  be  pasteurized, 
just  enough  for  the  mother-starter,  the  milk  can  be  put  di- 
rectly into  the  jars.  The  jar  half  full  is  about  the  proper  amount 
of  milk  to  use.  The  directions  sent  with  some  pure  cultures 
recommend  as  much  as  half  a  gallon  or  a  whole  gallon  of  milk. 
As  a  rule  better  results  are  obtained  if  only  about  a  pint  of 
milk  is  taken.  If  the  milk  for  the  mother-starter  is  pasteurized 
in  the  glass  bottles  or  jars,  then  it  is  advisable  to  set  the  bottles 


220  BUTTER-MAKING. 

containing  the  milk  into  cold  water, — covering  the  jar  so  as 
to  prevent  outside  contamination, — and  then  heat  up  the 
water  gradually.  Care  should  be  taken  not  to  insert  these 
bottles  suddenly  into  scalding  hot  water,  or  to  let  the  steam 
strike  them,  for  either  is  likely  to  crack  the  bottles.  Care 
should  be  taken  also  to  exclude  water  from  milk  used  for 
starters.  It  is  advisable  to  heat  this  milk,  for  the  starterline, 
as  high  as  possible  in  scalding  water,  say  up  to  about  200°  F. 
The  sample  may  assume  a  cooked  taste,  but  this  will  soon 
disappear  after  the  starter  has  been  carried  on  a  few  days. 
The  milk  should  be  left  at  this  high  temperature  for  about  ten 
or  fifteen  minutes.  A  longer  time  does  no  harm.  Then  the 
milk  is  gradually  cooled  to  about  80°  F.  This  high  temperature 
is  desirable,  because  the  germs  present  in  the  commercial  cul- 
ture may  be  somewhat  dormant.  This  high  temperature  would 
tend  to  revive  them  more  quickly  than  a  lower  temperature. 
Great  care  should  always  be  taken  to  cool  the  milk  previous  to 
inoculating  it  with  the  pure  culture,  otherwise  the  germs  present 
in  the  pure  culture  .will  be  destroyed. 

Inoculation,- — The  next  step  is  to  inoculate  the  prepared 
milk  with  the  pure  culture  obtained  from  the  laboratory.  The 
bottle  which  contains  the  pure  culture  is  carefully  opened,  then 
the  bottle  containing  the  culture  is  turned  over  and  emptied 
into  the  pasteurized  milk.  The  bottle  should  be  held  down 
closely  to  the  mouth  of  the  jar  containing  the  sterile  milk,  in 
order  to  prevent  too  much  contamination  from  the  air.  Then 
the  milk  containing  the  pure  culture  is  thoroughly  stirred  and 
set  away  in  a  room  where  the  temperature  is  about  70°  F. 
This  will  gradually  cool  the  milk  from  80°  to  70°  F.,  and  in 
about  twenty  to  forty  hours  the  milk  will  sour  and  coagulate. 
Germs  in  nearly  all  of  the  liquid  cultures  are  rather  slow  in 
acting  upon  the  milk,  undoubtedly  due  to  the  dormancy  of  the 
germs,  and  to  a  comparatively  few  of  them  being  present  in 
the  pure  culture.  When  the  powdered  cultures  are  used,  a 
little  more  care  is  essential  to  get  the  powder  thoroughly  min- 
gled with  the  milk.  It  is  a  trifle  more  difficult  to  get  the 


STARTERS.  221 

powder  thoroughly  mixed  with  the  milk  than  it  is  to  get  the 
liquid  cultures  mixed.  If  anything  is  used  with  which  to  stir 
the  sample,  it  should  be  sterilized  before  coming  in  contact 
with  the  milk.  This  applies  in  the  preparation  of  all  cultures. 
In  testing  or  sampling  the  mother-starters,  nothing  should  be 
allowed  to  come  in  contact  with  it  unless  it  has  previously  been 
thoroughly  sterilized.  The  powder  cultures  are  usually  more 
vigorous  in  their  effect  than  most  of  the  liquid  cultures  now 
on  the  market.  The  powder  cultures  usually  coagulate  the 
sample  in  about  twenty-four  hours,  and  if  the  operator  is  used 
to  handling  the  liquid  cultures,  he  should  watch  the  mother- 
starters  prepared  from  powder  cultures,  so  that  they  do  not 
get  overripe.  It  is  very  essential  that  the  starters  do  not  get 
overripe.  The  time  when  the  germs  are  most  numerous  and 
most  active  in  the  starter  is  about  the  time  when  the  sample 
coagulates.  As  soon  as  this  stage  has  been  reached,  or  just 
previous  to  coagulation,  the  starter  should  be  cooled  down  to 
at  least  50°  F.,  or  lower  if  possible  This  prevents  any  further 
growth  of  germs  and  the  sample  can  be  kept  a  short  time 
without  injury. 

Directions  usually  accompany  each  of  the  cultures,  but  the 
above  will  be  found  to  produce  good  results  with  all  of  those 
mentioned  in  the  above  outline. 

By  inoculating  from  2%  to  5%  or  more  of  the  mother- 
starter  into  a  large  sample  of  pasteurized  milk,  any  desired 
amount  of  starter  can  be  prepared.  In  selecting  this  amount 
of  milk,  as  much  care  as  possible  should  be  taken  in  order  to 
select  the  best  kind  of  milk,  and  keep  it  from  being  contaminated. 
When  this  large  sample  of  starter  is  at  the  proper  stage  of 
coagulation,  it  should  be  used  at  once,  or  else  cooled  down  to 
about  50°  F.  The  amount  of  mother-starter  with  which  to 
inoculate  the  large  sample  of  starter  may  vary  a  little  with- 
out any  bad  effects.  If  the  large  sample  of  starter  is  to  be 
ready  for  use  in  a  short  time,  a  larger  portion  of  the  mother- 
starter  can  be  used  for  inoculation.  If  the  temperature  at 
which  the  starter  is  set  and  the  amount  of  mother-starter  used 


222  BUTTER-MAKING. 

for  inoculation  are  the  same  from  day  to  day,  the  starter  will 
be  ripe  at  nearly  the  same  hour  every  day,  and,  consequently, 
more  uniform  ripening  results  can  be  obtained.  The  notice- 
able coagulation  of  the  starter  when  skim-milk  is  used  will 
usually  take  place  when  there  is  about  .6%  of  acidity.  A 
slight  coagulation  will  take  place  when  there  is  about  .5%  of 
acidity,  but  it  is  hardly  noticeable.  The  coagulation-point  may 
vary  with  different  samples  of  milk. 

If  a  mother-starter  is  to  be  kept  any  length  of  time  it 
should  be  inoculated  into  a  sample  of  good  fresh  pasteurized 
milk  about  every  other  day.  If  a  mother-starter,  or  starter 
of  any  kind,  is  allowed  to  stand  too  long  at  a  low  temperature, 
the  desirable  germs  will  become  dormant,  and  some  undesirable 
germs  will  gradually  gain  a  foothold.  It  is  a  good  plan  to 
carry  any  mother-starter  along  for  two  or  three  days  before  it 
is  used  to  inoculate  a  large  sample  of  milk.  When  the  mother- 
starter  is  first  prepared  it  sometimes  contains  an  undesirable 
taste  and  smell  from  the  medium  in  which  the  germs  were 
put  up  at  the  laboratory.  This  smell  and  taste  is  eliminated 
by  carrying  it  on  two  or  three  days  previous  to  its  use. 

While  the  starter,  or  mother-starter,  is  in  the  stage  of 
ripening  it  should  occasionally  be  gently  stirred.  As  soon  as 
coagulation  of  the  milk  begins,  then  starters  of  any  kind  should 
never  be  stirred.  If  a  sample  of  coagulated  milk  is  stirred 
before  it  is  ready  for  use,  it  is  more  likely  to  "whey  off." 

Length  of  Time  a  Starter  Can  be  Carried. — In  this  country, 
even  if  special  precautions  are  taken,  it  seems  almost  im- 
possible to  carry  on  a  starter  for  more  than  four  weeks  without 
having  undesirable  ferments  enter.  The  length  of  time  a  starter 
can  be  carried  undoubtedly  depends  upon  conditions,  and  the 
care  with  which  it  has  been  handled.  When  a  starter  is  properly 
prepared,  cooled  gradually  before  coagulation,  and  not  overri- 
pened,  it  will  contain  a  smooth-soft  curd,  and  retain  its  mild  acid 
flavor  for  at  least  a  month.  The  Danes,  who  use  starters  in 
butter-making  more  regularly  than  any  other  people,  are  able  to 
carry  a  starter  along  for  six  months  or  more  without  renewing  it. 


STARTERS.  223 

It  is  a  good  plan  to  keep  at  least  two  different  kinds  of 
starter  by  carrying  them  9n  from  day  to  day  in  small  quart 
jars.  Then  if  one  should  happen  to  "go  off/'  the  other  one 
can  be  used  instead. 

Poor  Starters.  —  Many  unsuccessful  results  from  the  use  of 
starters  for  cream-ripening  have  been  reported.  The  failure 
can  be  traced  to  the  improper  use  of  starters.  If  starters  are 
good  they  will  never  bring  about  poorer  results  than  are  ob- 
tained without  the  use  of  them.  Owing  to  the  fact  that  it  is 
difficult  to  keep  the  same  starter  in  a  good  condition  very 
long,  many  starters  are  used  which  develop  abnormal  fermenta- 
tions in  cream.  A  slightly  acid,  somewhat  bitter  taste,  and  a 
slimy  condition  of  the  starter  are  defects  which  are  very  com- 
mon. These  conditions  seem  to  be  brought  about  chiefly  by 
overripening  it  at  a  high  temperature,  and  keeping  it  a  long 
time  at  a  low  temperature  before  using  it.  Slimy  fermenta- 
tion is  very  common  in  starters  which  have  been  carried  on 
for  a  time,  Whenever  this  slimy  ferment  develops  in  the 
starter  it  can  be  noticed  in  the  cream  and  starter  both,  by  the 
acid  not  developing  so  rapidly  as  when  the  proper  acid-pro- 
ducing ferment  is  present.  It  seems  almost  impossible  to 
develop  any  more  than  about  .5%  of  acidity  in  30%  cream; 
while  if  the  proper  ferment  were  present,  about  .7%  could  be 
developed.  A  decrease  in  the  quality  of  butter  accompanies 
the  development  of  this  ferment  in  the  cream. 

Whenever  it  is  found  that  a  starter  is  not  in  as  good  condi- 
tion as  it  ought  to  be,  it  should  not  be  used,  as  a  poor  starter 
is  worse  than  none  at  all.  The  buttermilk  from  the  previous 
cream  can  sometimes  be  used  advantageously  until  a  new 
starter  can  be  prepared. 

Underripening  and  Overripening  of  Starters.  —  The  effect 
of  overripening  starters  has  already  been  mentioned  under  the 
"Preparation  of  Mother-starters."  The  question  of  under- 
ripening  starters  is  also  of  importance.  It  is  a  well-known  fact 
that  just  about  the  time  when  the  milk  begins  to  turn  sour, 
that  is,  when  the  sourness  can  just  be  recognized  by  the  taste, 


224  BUTTER-MAKING. 

it  has  a  rather  disagreeable  flavor.  After  more  acid  develops 
the  undesirable  flavor  largely  disappears,  and  the  milk  assumes 
a  clean,  desirable  acid  taste.  The  reasons  for  this  has  recently 
been  accounted  for  by  S torch,  the  well-known  authority  on 
starters.  He  claims  that  this  disagreeable  flavor  is  due  to  the 
action  of  undesirable  organisms,  during  the  first  souring  stage. 
As  the  souring  progresses  these  germs  are  subdued  and  grad- 
ually crowded  out  by  the  desirable  acid-producing  types. 

In  the  preparation  of  a  starter  the  probabilities  are  that 
some  of  these  undesirable  types  of  germs  are  present.  At  least 
it  is  safer  to  go  on  the  assumption  that  they  are  present.  This 
makes  the  underripening  of  starters  just  as  important  to  guard 
against  as  overripening. 

Amount  of  Starter  to  Use. — The  amount  of  starter  will  vary 
under  different  conditions.  It  may  vary  from  none  at  all  the 
as  much  as  50%  of  the  cream  to  be  ripened.  The  quality  of 
cream  is  one  of  the  factors  that  needs  to  be  considered.  Raw 
cream  and  old  cream  each  require  a  large  starter,  especially  if 
the  cream  is  thick  enough  so  as  to  permit  of  being  reduced  in 
thickness.  Good  pasteurized  cream  does  not  need  a  larger 
starter  than  about  10%  of  the  cream  to  be  ripened. 

The  amount  of  starter  to  use  also  depends  somewhat  upon 
the  general  creamery  conditions.  In  some  creameries  all  the 
cream  is  received  in  a  very  sour  and  poor  condition,  and  facili- 
ties for  getting  milk  for  preparation  of  starters  are  often  very 
poor.  Under  such  conditions  it  is  questionable  whether  it 
would  be  profitable  to  use  starters  at  all.  The  amount  of 
starter  to  use  chiefly  depends  upon  the  degree  of  rapidity  of 
ripening  desired,  .and  upon  the  temperature  of  the  cream.  If  it 
is  desirable  to  ripen  quickly,  then  a  comparatively  large  starter 
(15%  to  25%)  should  be  added,  and  the  ripening  temperature 
should  be  comparatively  high  (about  80°  F.).  If  slow  ripening 
is  desired,  then  less  starter  can  be  used.  Enough,  however,  should 
be  used  to  control  the  fermentation  in  the  cream  (about  10% 
to  15%),  and  the  ripening  temperature  may  be  lower,  between 
60°  and  70°  F.  More  starter  should  be  used  in  the  winter. 


STARTERS. 


225 


Use  of  Starter-cans. — In  the  past,  ordinary  tin  shot-gun 
cans  have  chiefly  been  used  for  the  preparation  of  starters, 
and  have  given  good  results.  Many  makers  still  use  such  cans 
in  preference  to  recently  invented  starter-cans. 


FIG.  133.— The  Victor 
starter-can. 


FIG.  134. — Emily's  perfection 
starter-can. 


The  earliest  starter-cans  were  made  of  light  material  and  did 
not  last  long.  These  defects,  however,  have  largely  been  done 
away  with,  and  the  use  of  starter-cans  certainly  is  an  improve- 
ment over  the  old  method  of  preparing  the  starters  in  several 
smaller  cans. 

These  starter-cans  are  jacketed,  so  that  the  temperature  can 
be  controlled  by  using  hot  or  cold  water,  or  ice,  as  demanded, 
in  the  jacket.  All  of  the  starter-cans  have  an  agitator,  which 
is  operated  with  a  belt. 


CHAPTER  XVI. 

CHURNING  AND  WASHING  BUTTER. 

Definition.— By  churning  we  understand  the  agitation  of 
cream  to  such  an  extent  as  to  bring  the  fat-globules  together 
into  masses  of  butter  of  such  size  as  to  enable  the  maker  to 
separate  them  from  the  buttermilk. 

The  agitation  may  be  brought  about  in  several  different 


FIG.  135. — Ancient  method  of  churning 
in  skin  bags. 


FIG.  136.— The  Dash  churn. 


ways,  and  by  different  shaped  devices,  which  are  called  churns. 
The  methods  of  churning,  like  the  process  of  separation,  began 
with  primitive  methods.  The  ancients  churned  their  milk, 
without  separation,  in  bags  made  from  the  skins  of  animals. 
The  next  step  in  advance  was  to  place  milk  or  cream  in  bottles 
or  jars,  and  then  to  shake  them.  This  latter  method  of  churn- 

226 


CHURNING  AND  WASHING  BUTTER.  227 

ing  cream  in  bottles  is  yet  in  use  in  many  of  the  smaller  house- 
holds of  Europe,  where  the  amount  of  cream  is  limited  to  a 
small  quantity  donated  by  cow-owners.  The  next  step  toward 
churning  on  a  large  scale  was  to  get  a  large  wooden  box  or 
barrel  run  by  power  or  by  hand.  The  churns  which  are  in  use 
at  the  present"  time  in  American  butter-factories  are  termed 
"  combined  churns."  They  are  so  arranged  as  to  admit  of 
churning,  washing,  salting,  and  working  without  removing  the 
butter  from  the  churn.  This  style  of  churn  is  now  being  in- 
troduced into  Europe.  Owing  to  their  superior  worth  they  will 
soon  be  in  general  use  there  as  well  as  here.  They  keep  flies 
away  from  the  butter  during  fly  time;  the  temperature  of  the 
butter  can  be  controlled  in  the  churn,  and  the  handling  of  the 
butter  during  salting  and  working  is  obviated. 

CONDITIONS  AFFECTING  THE  CHURNABILITY  OF  CREAM. 

Temperature. — The  temperature  of  cream  is  one  of  the  most 
influential  factors  in  determining  the  churnability  of  cream. 


FIG.  137. — The  Dairy  Queen  combined  churn. 

The  higher  the  temperature  of  the  cream,  the  sooner  the  churn- 
ing process  will  be  completed.  Too  high  a  churning  tempera- 
ture, however,  is  not  desirable.  It  causes  the  butter  to  come 
in  soft  lumps  instead  of  in  a  flaky  granular  form.  This  is 
deleterious  to  the  quality  of  the  butter.  It  causes,  first,  a  greasy 
texture  of  the  butter,  and,  secondly,  it  causes  the  incorporation 


228 


BUTTER-MAKING, 


in  the  butter  of  too  much  buttermilk.  This  buttermilk  contains 
sugar,  curd,  and  water,  which,  when  present  together  in  butter, 
are  likely  to  sour  and  in  other  ways  deteriorate  the  butter. 
Curd  and  sugar  should  be  excluded  from  butter  as  much  as 
possible,  in  order  to  eliminate  food  for  bacteria  which  may  be 
present.  An  excess  of  curd  is  also  favorable  for  the  forma- 
tion of  mottles.* 

Too  low  a  temperature  is  also  undesirable,  although  it  is 


FIG.  138. — The  Victor  combined  churn. 

better  to  have  the  temperature  a  little  low  rather  than  too  high. 
When  the  churning  temperature  is  too  low,  difficult  churning 
is  likely  to  occur.  Cream  at  a  low  temperature  becomes  more 
viscous.  On  agitation  in  the  churn  such  cream  if  it  is  very 
thick  will  adhere  to  the  sides  of  the  churn  and  rotate  with  .'t 
without  agitating;  consequently  no  churning  will  take  place. 
Too  low  a  temperature  brings  the  butter  in  such  a  firm  condi- 
tion that  it  takes  up  salt  with  difficulty,  and  when  this  hard 
butter  is  being  worked,  a  large  portion  of  the  water  in  ihe 

*  Bui.  No.  263,  Geneva,  N.  Y. 


CHURNING  AND  WASHING  BUTTER.  229 

butter  is  expressed,  and  the  overrun  will  be  lessened  to  a  great 
extent  without  increasing  the  commercial  value  of  the  butter. 

The  degree  of  hardness  of  the  fat  in  the  cream  is  the  govern- 
ing factor  in  deciding  the  churning  temperature.  The  churn- 
ing temperature  will  vary  a  great  deal  in  different  localities. 
The  hardness  of  the  fat  depends  upon  (1)  the  season  of  the  year; 
(2)  the  individuality  of  cow;  (3)  the  stage  of  lactation  period; 


FIG.  139. — The  Squeezer  combined  churn. 

and  (4)  the  kind  of  food  fed  to  the  cows.  All  these  factors 
influence  the  melting-point  of  butter-fat,  The  higher  the 
melting-point  of  butter-fat  is,  the  higher  the  churning  tempera- 
ture, and  the  lower  the  melting-point  of  the  fat,  the  lower  the 
churning  temperature. 

1.  During  the  spring  the  cows  yield  milk  containing  a  larger 
proportion  of  soft  fats;    consequently  the  churning  tempera- 
ture is  always  lower  in  the  spring  than  in  the  fall  or  winter. 
During  winter,  when  the  cows  are  fed  on  dry  food  chiefly,  the 
harder  fats  increase  in  quantity,  and  consequently  a  higher 
churning  temperature  is  necessary  during  that  time. 

2.  Some  animals  produce  milk  containing  a  larger  proportion 
of  softer  fats  than  do  other  animals.    It  is  said  that  the  differ- 
ence in  this  respect  is  more  marked  in  certain  breeds.    It  is 
maintained  that  the  cows  of  the  Jersey  breed  produce  milk  con- 
taining a  larger  proportion  of  the  softer  fats  than  do  any  of  the 
other  breeds. 

3.  The  period  of  lactation  also  affects  the  melting-point  of 
butter-fat.    When  a  cow  is  fresh  she  yields  a  larger  proportioE 


230 


BUTTER-MAKING. 


of  the  soft  fats  than  she  does  later  on  in  the  lactation  period. 
With  this  increase  in  the  proportion  of  the  hard  fats  in  the 
advancement  of  the  lactation  period,  the  fat-globules  become 
smaller.  This,  together  with  the  increased  hardness  of  the  fat, 
causes  difficult  churning  at  times.  It  can  readily  be  seen  that 
the  larger  the  fat-globules  are  the  greater  are  the  chances  for 
these  globules  to  strike  each  other  during  agitation  in  the 
churning  process. 

4.  The  nature  of  the  food  fed  affects  the  melting-point  of 
butter   to   a   considerable   extent.    Cotton-seed   and   its   by- 


FIG.  140. — The  Disbrovv  combined  churn. 

products  have  been  demonstrated  thoroughly  by  several  investi- 
gators to  cause  butter  to  become  hard.  When  a  large  amount 
of  cottonseed  is  fed,  the  butter  assumes  a  crumbly,  tallowy, 
hard  condition;  while  linseed  meal,  and  practically  all  succulent 
foods  tend  to  decrease  the  melting-point  of  butter-fat. 

According  to  the  above  it  can  be  concluded  that  the  churning 
temperature  may  vary  between  wide  limits,  but  the  average 
desirable  churning  temperature  under  normal  conditions  is 


CHURNING  AND  WASHING  BUTTER. 


231 


between  50°  and  60°  F.  Any  conditions  which  tend  to  harden 
the  butter-fat  will  require  a  comparatively  high  churning  tem- 
perature; and  any  conditions  tending  to  soften  the  butter-fat 
will  require  a  lowering  of  the  churning  temperature.  The 
lower  the  temperature  at  which  the  churning  can  be  success- 
fully accomplished,  the  more  complete  will  be  the  churning; 
that  is,  the  less  fat  will  remain  in  the  buttermilk. 


FIG.  141. — The  Simplex  combined  churn,  with  worker  detached. 

Richness  of  Cream. — The  amount  of  fat  in  the  cream  affects 
the  churnability  of  it  considerably.  The  richer  the  cream  the. 
sooner  will  be  the  completion  of  the  churning,  that  is,  providing 
the  cream  is  not  rich  enough  to  be  so  thick  as  to  cause  the  cream 
to  adhere  to  the  inside  of  the  churn  and  thus  escape  being 
agitated.  If  rich  cream  is  churned  at  a  high  temperature  the 
butter  will  come  in  a  remarkably  short  time,  providing  all  other 


232  BUTTER-MAKING. 

conditions  are  favorable.  Thin  cream  churns  much  more  slowly, 
and  can  be  churned  at  a  higher  temperature  than  thick  cream, 
without  injuring  the  quality  of  the  butter.  When  rich  cream 
is  churned  at  a  high  temperature,  and  the  butter  comes  in  a 
short  time  (about  ten  minutes),  the  butter  will  usually  be  greasy 
in  body,  and  will  contain  a  great  deal  of  buttermilk,  which  will 
be  more  or  less  difficult  to  remove  on  washing.  When  thick 
cream  is  being  churned,  the  butter  does  not  break  in  the  form 
of  small  round  granules,  as  it  does  when  thin  cream  is  churned. 
When  thick  cream  is  churned  at  as  high  a  temperature  as  is 
consistent  with  getting  a  good  texture,  the  best  results  are 
obtained.  In  the  first  place,  rich  cream  produces  less  butter- 
milk, consequently  less  fat  will  be  lost  in  the  buttermilk.  This 
would  tend  to  increase  the  overrun.  Secondly,  the  breaking 
of  the  butter  at  the  end  of  the  churning  will  be  such  as  to 
cause  the  granules  to  appear  large  and  flaky,  rather  than  small 
round  granules.  The  more  flaky  granules  of  butter  will  retain 


FIG.  142. — The  Simplex  churn  with  worker  attached. 

more  moisture  than  the  small,  harder  granules  under  the  same 
treatment.  Experiments  show  that  when  different  thicknesses 
of  cream  (thin  cream  containing  on  an  average  22%  of  fat, 
and  thick  cream  36%  of  fat)  are  churned,  there  is  a  difference 
of  about  3%  in  the  moisture- content  of  the  butter.  The 


CHURNING  AND  WASHING  BUTTER. 


233 


average  churning  temperatures  of  cream  and  wash-water  in  these 
experiments  were  56°  and  53°  F.  respectively. 

When  thick  cream  is  churned,  and  the  temperature  is 
moderately  high,  it  is  almost  impossible  to  churn  the  butter 
into  granules.  This  condition  causes  butter  from  thick  cream 
to  contain  more  moisture  than  butter  from  thin  cream. 

Amount  of  Cream  in  Churn. — When  the  churn  is  about  one- 
third  full,  the  greatest  degree  of  agitation  is  obtained,  and  con- 


FIG.  143. — Danish  churns  and  frame  for  holding  them. 

sequently  a  quicker  churning.  If  a  small  amount  of  cream  is 
being  churned,  it  is  often  difficult  to  gather  the  butter  properly. 
If  the  cream  is  thin,  the  granules  are  thrown  about  in  such  a 
way  that  they  are  gathered  with  difficulty.  If  the  cream  is 
thick,  the  small  amount  of  cream  will  adhere  to  the  inside  of  the 
churn,  and  in  that  way  delay  the  completion  of  the  churning. 
It  is  a  common  opinion  that  less  overrun  is  obtained  from 


234  BUTTER-MAKING. 

a  small  churning  than  from  a  large  churning.  It  is  safe  to  say 
that  if  it  were  possible  to  maintain  all  conditions  alike,  especially 
as  to  temperature  and  degree  of  churning,  there  would  be  no 
difference  in  the  moisture-content  of  the  butter  made  from 
churnings  of  different  sizes.  When  there  is  only  a  small  amount 
in  the  churn,  the  atmospheric  temperature  is  likely  to  raise  or 
lower  the  temperature  of  the  cream.  If  the  atmosphere  is 
warm,  then  the  butter  from  the  small  churning  is  more  likely 
to  be  soft.  A  small  amount  of  cream  in  the  churn  is  also  more 
likely  to  be  overchurned  than  a  larger  amount  of  cream.  These 
two  factors  would  tend  to  increase  the  amount  of  water  in  the 
butter.  In  mixing  the  salt  with  a  comparatively  large  amount 
of  butter,  less  working  is  necessary.  Much  of  the  butter  is 
mixed  in  the  churn  without  going  through  the  workers,  and  con- 
sequently less  moisture  will  be  expressed  from  the  butter.  With 
the  same  number  of  revolutions  of  the  churn  the  butter  from 
the  small  churning  is  worked  correspondingly  more  than  the 
butter  from  a  larger  churning.  Medium  firm  butter,  to  a  cer- 
tain limit,  loses  about  .2%  of  moisture  for  every  revolution  that 
it  is  overworked  in  the  absence  of  water. 

Degree  of  Ripeness. — The  riper  the  cream  is,  all  other  con- 
ditions being  the  same,  the  easier,  it  will  churn.  Sweet  cream 
is  viscous,  and  consequently  the  fat-globules  will  not  unite  as 
readily.  The  acid  developed  in  the  cream  seems  to  cut  or 
reduce  the  viscosity  of  the  cream,  although  it  causes  it  to  become 
thicker  in  its  consistency.  Cream  in  an  advanced  stage  of 
ripening  is  brittle,  so  to  speak.  That  is,  if  a  sample  of  the 
properly  soured  cream  is  poured  from  a  dipper  it  will  not  string 
but  break  off  in  lumps. 

If  very  thin  cream  is  overripened,  the  curd  is  coagulated. 
When  this  thickly  coagulated  cream  is  churned,  the  solid  curd 
breaks  up  into  small  curdy  lumps.  These  small  lumps  of  curd 
are  likely  to  incorporate  themselves  in  the  body  of  the  butter 
and  injure  its  quality,  and  also  its  keeping  quality.  If  thin 
cream  has  been  overripened,  it  should  be  strained  well,  and 
care  should  be  taken  not  to  churn  it  to  such  a  degree  as  to 


CHURNING  AND  WASHING  BUTTER.  235 

unite  the  granules  into  lumps  before  the  churn  is  stopped.  By 
stopping  the  churn  while  the  butter  is  in  a  granular  form,  the 
most  of  these  curdy  specks  can  be  separated  from  the  butter 
by  copious  washing.  Some  specks  are  likely  to  remain  in  the 
butter  when  the  cream  is  in  such  a  condition,  but  by  following 
the  above  plan  enough  of  the  specks  can  be  removed  from  the 
butter  so  that  it  will  not  injure  its  commercial  quality.  The 
degree  of  ripeness  of  cream  does  not  have  any  effect  upon  the 


FIG.  144. — The  churn-room  in  Trifolium  Creamery,  Denmark. 

composition  of  the  butter,  except  in  increasing  the  curd  con- 
tent, as  mentioned. 

Nature  of  Agitation. — The  nature  and  degree  of  agitation  of 
cream  affect  the  churnability  considerably.  Many  different 
kinds  of  churns  are  on  the  market  at  the  present  time.  The  ro- 
tary drum-churns,  now  used  almost  universally  in  this  country, 
are  claimed  to  give  the  greatest  degree  of  agitation;  that  is, 
providing  the  churn  revolves  at  a  proper  rate  of  speed.  If 


236  BUTTER-MAKING. 

the  speed  is  so  great  as  to  cause  the  cream  to  be  influenced  by 
the  centrifugal  force  generated,  rotating  it  with  the  churn, 
then  no  agitation  will  take  place.  Consequently  the  churning 
process  will  be  delayed,  if  not  entirely  prevented.  If  the 
speed  of  the  churn  is  too  slow,  the  degree  of  agitation  of 
the  cream  will  not  be  at  its  maximum,  as  the  cream  will  tend 
to  remain  at  the  lowest  portion  of  the  churn  without  being 
agitated. 

In  the  old-fashioned  dash-churn  the  cream  was  not  exposed 
to  much  agitation.  In  Europe  the  upright  barrel-churn  with 
rotary  stirrers  inside  is  mostly  used.  It  takes  longer  to  churn 
in  this  churn  than  in  American  churns.  However,  it  gives  good 
satisfaction. 

The  proper  speed  of  the  combined  churn, — that  is,  the  speed 
at  which  the  greatest  degree  of  agitation  is  brought  about,— 
cannot  be  given  here,  as  it  varies  with  the  different  diameters 
of  the  churns.  The  directions  given  with  the  churns  from  the 
manufacturing  companies  should  be  followed.  So  far  as  known 
the  quality  and  composition  of  butter  obtained  from  churning 
at  a  low  speed,  and  at  a  rapid  speed,  do  not  vary. 

Size  of  Fat-globules. — Cream  containing  large  fat-globules 
churns  more  quickly  than  cream  containing  small  globules.  A 
more  exhaustive  churning  can  also  be  obtained  from  cream 
containing  mostly  large  globules.  It  is,  however,  impossible 
to  obtain  cream  which  does  not  contain  any  of  the  small  globules. 
The  minute  globules  are  always  difficult  to  remove  from  the 
serum,  whether  it  be  in  the  churning  or  in  the  separation.  In 
the  churning  there  is  a  certain  force  which  always  tends  to  hold 
the  globules  in  place.  This  force  acts  in  a  correspondingly 
greater  degree  upon  the  small  globules.  They  are  held  in 
position  and  move  only  when  the  cream  is  exposed  to  agitation. 
Cream  containing  larger  globules  allows  them  to  escape  from 
their  position  with  greater  ease  than  does  cream  containing 
the  minute  globules.  The  globules  which  are  not  removed  from 
the  buttermilk  during  the  churning  process  are  largely  of  the 
small  type. 


238  BUTTER-MAKING. 

Straining  of  Cream. — Before  the  cream  is  transferred  from 
the  ripening-vat  to  the  churn  it  should  be  strained  through  a 
fine  perforated  tin  strainer.  This  can  be  conveniently  done 
during  the  changing  of  the  cream  from  the  ripening-vat  to  the 
churn.  Special  strainers  are  now  manufactured  which  can 
be  hooked  onto  the  churn,  and  the  cream  can  run  directly  from 
the  ripening-vat  through  the  strainer  into  the  churn.  This 
straining  of  the  cream  separates  all  the  lumps  which  are 
likely  to  appear.  It  also  separates  any  other  coarse  impurities 
which  may  be  present.  If  these  impurities  were  not  sepa- 
rated they  would  probably  be  embodied  in  the  butter  and 
cause  an  unsightly  appearance.  They  would  also  be  likely  to 
injure  the  keeping  quality  of  the  butter,  but  this  would  depend, 
of  course,  upon  the  character  of  the  impurities. 


FIG.  146. — Cream  and  milk  strainer. 

Color. — In  order  to  maintain  a  uniform  color  in  the  butter 
during  the  different  seasons,  it  is  essential  that  some  artificial 
color  be  added  at  certain  times.  During  the  latter  part  of 
May  and  the  fore  part  of  June  the  butter  has  a  rich  yellow 
color,  which  is  accepted  as  the  standard  color  of  butter.  This 
is  often  referred  to  as  the  "June  color." 

There  are  several  different  butter-colors  on  the  market,  for 
which  special  merits  are  claimed.  All  the  colors,  so  far  as 
known,  are  efficient  in  imparting  color  to  the  butter  without 
materially  coloring  the  buttermilk.  A  good  butter- color  should 
be  a  substance  which  does  not  impart  a  bad  smell  or  taste  to 
the  butter.  It  should  possess  strong  coloring  properties,  so 
that  very  little  of  it  would  have  to  be  added  in  order  to 
impart  the  desirable  color.  It  should  not  be  injurious  to  health. 


CHURNING  AND  WASHING  BUTTER.  239 

Some  colors  are  prepared  from  the  fruit  of  the  annato  tree, 
which  grows  in  the  East  Indies  and  South  America.  The  flesh 
of  this  fruit  is  dissolved  in  some  oil,  such  as  sesame  or  hemp. 

Before  any  of  the  proper  commercial  butter-colors  were  put 
upon  the  market,  extracts  of  carrots,  marigold,  saffron,  and 
annato  were  used.  The  yolk  of  eggs  has  also  been  used  to 
some  extent.  It  is  said  that  carrot-juice  is  the  most  healthful 
butter-color. 

The  amount  of  color  to  add  depends  upon  the  market 
requirements,  and  upon  the  season  of  the  year.  As  was  men- 
tioned before,  in  June  little  or  no  color  should  be  added.  As 
the  summer  season  advances  the  amount  of  color  added  can  be 
gradually  increased.  During  winter,  while  the  cows  are  on 
dry  feed,  the  maximum  amount  of  color  is  generally  used.  Color 
requirements  of  the  butter  vary  considerably  at  the  same  season 
of  the  year.  American  markets  demand  a  higher  color  than 
European  markets.  The  northern  markets  desire  a  light  straw 
color,  while  the  southern  markets  want  a  deeper  color,  almost 
an  orange  color.  The  Jewish  trade  requires  uncolored  butter. 
In  some  of  the  European  countries  no  color  is  used.  The 
English  market,  which  is  the  greatest  butter  market  in  the 
world,  demands  butter  that  has  a  very  light  straw  color.  The 
main  object  in  coloring  butter  is  to  maintain  a  uniform  color 
during  the  different  seasons  of  the  year.  The  amount  of  color 
to  add  during  the  different  seasons  will  usually  vary  between 
none  to  a  trifle  over  two  ounces  for  every  100  pounds  of  fat. 

The  color  should  be  added  to  the  cream  before  the  churn 
has  been  started.  If  this  has  not  been  done,  the  butter  can  be 
colored  by  mixing  the  color  with  the  salt.  The  salt  should 
then  be  well  distributed  and  worked  into  the  butter  until  the 
body  of  the  butter  assumes  a  uniform  color.  The  chief  ob- 
jection to  this  method  is,  that  it  is  difficult  to  work  in  the  color 
thoroughly  without  injuring  the  butter. 

When  to  Stop  the  Churning. — Different  makers  have  various 
ways  of  ascertaining  when  the  churning  process  has  been  com- 
pleted. Some  determine  the  proper  churning  stage  by  the  size 


240  BUTTER-MAKING. 

of  granules.  Others  by  the  height  at  which  the  butter  floats 
in  the  buttermilk.  Others  again  depend  upon  the  appearance 
of  the  buttermilk.  It  is  well  to  let  all  of  these  factors  influence 
the  operator  in  deciding  when  the  churn  should  be  stopped. 
Any  one  of  these  factors  may  not  be  sufficient  indication  to 
insure  the  proper  time  to  stop. 

The  size  of  the-  granules  is  the  most  common  factor  that 
determines  the  time  when  the  churn  should  be  stopped.  It 
has  been  a  general  rule  in  the  past  to  stop  the  churning  when 
the  granules  are  a  little  larger  than  wheat-kernels.  As  a  rule 
it  is  safer  to  carry  the  churning  on  a  little  further  until  the 
granules  increase  to  the  size  of  corn-kernels,  irregular  and 
flaky  in  shape.  At  this  stage  the  buttermilk  will  usually  appear 
bluish  in  color,  and  the  butter  is  raised  above  the  buttermilk 
a  considerable  distance.  When  the  butter  is  churned  to  too 
small  granules,  many  of  them  will  go  through  the  strainer  into 
the  buttermilk,  and  cause  a  considerable  loss.  When  butter 
in  such  shape  is  washed  in  medium-cold  wash-water,  the  granules 
continue  to  remain  in  a. separate  state.  When  salt  is  added, 
the  moisture  is  extracted  from  them,  and  the  water  is  likely 
to  be  caught  in  holes  and  crevices  during  the  working  and 
cause  leaky  butter.  If  the  churning  is  carried  on  a  little  further, 
the  granules  will  not  escape  into  the  buttermilk.  The  churn- 
ing is  more  complete,  and  the  moisture  will  be  incorporated  in 
a  better  condition. 

Overchurning  should  be  avoided  as  much  as  underchurning. 
If  butter  is  overchurned  in  the  buttermilk,  it  will  retain  a 
large  amount  of  the  buttermilk,  which  will  be  very  difficult 
to  remove  by  washing.  Overchurning  butter,  especially  at  a 
medium-high  temperature,  is  very  effective  in  increasing  the 
moisture-content  of  butter,  and  should  be  guarded  against  for 
that  reason.  Butter  containing  more  than  16%  water  is  not 
permissible  on  the  American  market. 

When  cream  is  in  a  poor  condition  it  should  not  be  over- 
churned,  as  the  incorporation  of  buttermilk  produces  a  very 
rank  and  unclean  flavor  in  the  butter.  Cream  in  such  condi- 


CHURNING  AND  WASHING  BUTTER. 


241 


tion  also  contains  many  undesirable  germs,  which,  when  in- 
corporated into  the  butter,  will  cause  it  to  deteriorate  to  a  great 
extent.  When  the  cream  is  in  poor  condition,  the  churn  should 
be  stopped  as  early  as  is  consistent  with  the  completeness  of 
churning.  The  buttermilk  should  be  removed  and  the  butter 
washed  thoroughly  in  good  clean  and  pure  wash-water.  If 


FIG.  147.— Butter  from  1  Ib.  of  fat  in  cylinders,  showing  the  effect  of  differ- 
ent percentages  of  water  upon  quantity.  The  water-content  of  these 
samples  ranges  between  8%  and  19%. 


the  wash-water  is  added  while  the  butter  is  in  this  granular 
condition,  the  buttermilk  can  be  very  effectively  removed. 
If  one  washing  is  not  sufficient,  wash  three  or  four  times.  In 
such  a  case  the  temperature  should  be  low.  If  the  temperature 
of  the  wash-water  is  high,  and  the  butter  is  washed  excessively, 
it  will  contain  too  much  moisture  when  it  is  finished,  and  is 
likely  to  be  salvy.  By  washing  with  water  at  a  low  temperature 
the  butter  will  not  incorporate  so  much  water.  What  it  does 


242 


BUTTER-MAKING. 


FIG.  148. — Butter  sample, 
15.61%  water. 


FIG.  149. — Butter  sample, 
15.31%  water. 


FIG.  159. — Butter  sample,  13.37%  water;  leaky,  2%  brine. 

Microscopical  views  showing  condition  of  water  in  butter.  Fig.  148  shows  that 
the  water  has  been  incorporated  in  the  form  of  very  minute  particles. 
Storch  found  from  nine  million  to  sixteen  million  water  particles  per 
cubic  millimeter.  Such  butter  appears  dry  and  a  little  dull.  Fig.  149 
shows  the  water  incorporated  in  medium-small  particles.  There  was 
on  an  average  three  and  three-fifths  millions  of  water  particles  per  cubic 
millimeter  in  such  butter.  Fig.  150  shows  condition  of  water  in  leaky 
butter.  Storch  found  about  two  and  one-half  million  water  particles 
per  cubic  millimeter  in  butter  having  such  a  body.  (Views  by 
Storch.) 


CHURNING  AND  WASHING  BUTTER.  243 

incorporate  in  excess,  will,  as  a  rule,  be  expressed  during  the 
working  of  the  butter — a  result  due  to  its  firmness. 

If  the  attempt  is  made  to  incorporate  water  by  working 
the  butter  in  water  after  the  salt  has  been  added,  while  the 
butter  is  in  a  hard,  granular  condition,  it  will  usually  appear 
leaky. 

If  cream  is  in  a  good  condition,  overchurning  to  a  small 
extent  does  not  produce  any  bad  results.  The  germs  which 
are  present  in  pure  and  well-ripened  cream  are  not  deleterious 
to  the  keeping  quality  of  the  butter.  The  amount  of  butter- 
milk incorporated  in  the  butter  is  not  sufficient  to  cause  any 
bad  effects  upon  its  quality.  If  the  cream  is  in  proper  condi- 
tion it  is  difficult  to  incorporate  any  more  than  3%  of  curd 
into  the  butter.  While  overchurning  is  not  to  be  recommended, 
if  it  is  at  any  time  desirable,  it  should  be  done  in  the  wash- 
water  rather  than  in  the  buttermilk. 

Churning  Mixed,  Sweet,  and  Sour  Cream. — When  two  lots  of 
cream  are  to  be  churned,  one  sweet  and  the  other  sour,  they 
should  be  churned  separately.  If  the  two  lots  of  cream  are 
mixed  together,  the  sour  cream  churns  more  quickly  than  the 
sweet  cream.  As  a  consequence  the  churn  is  likely  to  be 
stopped  before  the  fat  from  the  sweet  cream  has  been  com- 
pletely separated  from  the  serum. 

At  some  of  the  creameries  conditions  are  such  that  the 
operator  may  be  tempted  to  mix  the  two  lots  of  cream.  Where 
sweet  cream  arrives  at  the  creamery  just  previous  to  churning 
time,  it  is  advisable  not  to  mix  the  sweet  cream  with  the  sour. 
It  is,  as  a  rule,  better  to  carry  the  sweet  cream  over  to  the 
next  churning,  or,  if  necessary,  churn  it  separately. 

Difficult  Churning. — Difficult  churnings  in  creameries  are 
not  very  common.  In  farm  butter-making  it  is  more  frequent. 
Especially  is  this  so  in  the  fall.  At  this  time  the  cows  are 
usually  well  advanced  in  the  period  of  lactation,  and  early  in 
the  winter  they  are  often  fed  on  food  which  causes  hard  butter- 
fat,  as  described  under  "Effect  of  Food  upon  Fat."  In  the 
fall  or  early  winter,  a  large  portion  of  the  milk  is  usually  obtained 


244  BUTTER-MAKING. 

from  strippers,  or  cows  almost  dried  up.  Such  milk  contains  a 
large  portion  of  the  small  fat-globules.  Difficult  churning 
resulting  from  such  conditions  can  usually  be  remedied  by 
ripening  to  a  higher  degree  of  acidity  and  churning  the  cream 
at  a  higher  temperature. 

Complaints  are  occasionally  heard  of  difficult  churning 
which  cannot  be  remedied  by  such  treatment.  Sometimes 
cream  froths,  and  will  not  agitate  in  the  churn.  Such  a  frothy 
condition  has  in  some  cases  been  found  to  occur  even  though 
the  cream  may  seem  to  be  in  an  ideal  condition  for  churning. 
It  is  believed  by  some,  notably  Hertz,  that  such  a  condition  in 
the  cream  is  brought  about  by  a  disease  of  the  cow.  Weigman 
has  studied  and  isolated  a  ferment  which  caused  a  soapy  condi- 
tion of  milk  and  cream.  It  is  possible  that  such  exceedingly 
difficult  cases  in  churning  may  be  due  to  a  disease  of  the  cow, 
and  it  may  also  be  due  to  certain  ferments  that  produce  a  soapy 
condition  of  the  cream. 

If  thick  cream  at  a  very  low  temperature  is  put  into  the 
churn,  it  sometimes  produces  difficult  churning.  When  such 
cream  is  first  agitated  in  the  churn  it  incorporates  considerable 
air.  This  air,  together  with  the  various  gases  developed  at  a 
low  temperature  does  not  readily  escape.  The  viscosity  of 
it  is  so  great  that  it  will  not  release  the  air  present.  As  a 
consequence  it  assumes  a  stiff  consistency,  much  the  same  as 
the  beaten  white  of  an  egg.  If  cream  froths  in  the  churn  as 
mentioned,  a  little  warm  water  thrown  on  the  outside  of  the 
churn  will  often  start  the  agitation  of  the  cream  within.  If 
a  combined  churn  is  used  the  rollers  may  be  put  in  gear,  and 
the  churn  revolved  in  slow  gear.  This  will  often  start  the 
cream  to  agitate.  If  these  two  remedies  are  not  sufficient,  a 
little  water,  luke-warm  if  necessary,  may  be  added  directly  to  the 
cream.  By  letting  the  churn  stand  a  short  time,  the  cream  will 
usually  condense  into  a  liquid  form  again,  and  many  times  the 
churning  process  can  then  be  completed.  This  latter  method,  how- 
ever, usually  requires  more  time  than  can  be  profitably  spared. 
If  the  churning  difficulty  is  of  a  serious  nature  the  remedies  are: 


CHURNING  AND  WASHING  BUTTER.  245 

(1)  If  produced  by  a  certain  cow,  or  herd,  find  out  whether 
it  is  produced  by  a  fermentative  process,  or  by  other  abnormal 
conditions  of  the  cow. 

(2)  Change   the  food  of  the  cow.     A  succulent  food  will 
usually  cause  the  cow  to  secrete  more  milk,  and  of  a  different 
nature. 

(3)  If  produced  by  a  ferment,  endeavor  to  control  the  fer- 
mentation as  previously  described. 

(4)  Ripen  the  cream  to  a  higher  degree  of  acidity. 

(5)  Skim  thicker  cream  and  churn  at  a  higher  tempera- 
ture. 

The  last  three  methods  will  cure  most  cases  of  difficult 
churnings. 

Keeping  Churn  Sweet. — It  has  been  mentioned  before  that 
butter  absorbs  foreign  odors  very  readily.  If  the  churn  is  not 
kept  in  a  pure,  sweet  condition,  the  butter  will  be  exposed  to 
the  undesirable  odors  and  its  commercial  quality  will  be  im- 
paired. The  best  butter  cannot  be  produced  in  a  foul-smelling 
churn.  As  churns  often  are  not  used  every  day,  they  very 
readily  assume  this  impure  condition,  and  it  is  essential  that 
special  care  be  taken  in  keeping  them  clean. 

The  best  method  of  keeping  churns  in  good  condition  is  to 
rinse  the  churn  in  two  sets  of  water  at  the  end  of  each  churn- 
ing. The  first  rinsing  should  be  made  with  lukewarm  water, 
the  second  with  scalding  hot  water.  Some  prefer  to  turn  the 
churn  over  with  mouth  down.  Others  prefer  to  allow  the 
cover-hole  to  turn  up.  When  the  churn  is  turned  with  the 
cover-hole  down,  the  remaining  steam  on  the  inside  of  the 
chum  will  not  escape.  It  will  condense  inside  of  the  churn, 
and  cause  the  churn  to  remain  in  a  damp  condition  over  night 
or  even  longer.  By  turning  the  churn  with  the  cover-hole  up 
the  dust  and  other  impurities,  if  present,  are  likely  to  settle 
into  the  churn.  A  good  way  is  to  turn  the  churn  over  so  that 
the  cover-hole  points  to  one  side.  The  churn  should  be  thor- 
oughly drained  first,  otherwise  some  water  will  remain  in  the 
bottom  of  the  churn.  When  the  churn  is  left  with  the  cover- 


246  BUTTER-MAKING. 

hole  at  one  side,  the  steam  can  escape,  and  the  heat  absorbed 
from  the  wash-water  will  dry  the  churn  thoroughly.  Many 
makers  rinse  the  chum  only  once  and  use  scalding  hot  water. 
This  method  is  likely  to  scald  the  remaining  curd  on  to  the 
wood;  secondly,  one  rinsing  is  not  enough  to  insure  a  clean  churn. 
The  first  rinsing  with  lukewarm  water  removes  the  major  por- 
tion of  the  buttermilk  and  brine,  and  to  a  certain  extent  warms 
the  wood  of  the  churn,  so  that  when  the  second  rinsing  with 
scalding  hot  water  is  completed,  the  churn  has  been  thoroughly 
scalded.  In  addition,  the  churn  is  clean,  and  no  food  left,  on 
which  for  germs  to  thrive.  The  chum  is  also  left  warm,  and  in 
that  condition  will  dry  quickly. 

Some  makers  prefer  to  keep  the  churn  in  a  good  condition 
by  sprinkling  salt  on  the  inside  after  washing.  This  is  not  to 
be  recommended,  as  all  churns  contain  more  or  less  iron-ware 
on  the  inside.  Salt,  while  a  good  germicide,  causes  the  forma- 
tion of  rust  on  all  iron  with  which  it  comes  in  contact.  After 
a  time  this  rust  will  scale  off  to  a  certain  extent  and  become 
incorporated  with  the  butter. 

If  the  churn  is  treated  daily  in  the  manner  described  above 
and  then  at  the  end  of  the  week  treated  with  slacked  lime,  the 
churn  can  be  kept  in  a  good  sweet  condition.  The  lime  should 
be  freshly  slacked  and  in  a  liquid  condition  when  put  in  the 
churn.  A  pailful  or  two  of  this  fluid  will  be  sufficient  for  each 
churn.  By  rotating  the  churn  a  few  times  the  lime  will  be 
spread  all  over  the  inside  of  the  churn.  Let  the  churn  remain 
in  this  condition  until  ready  for  use  again.  When  ready  for 
use,  put  in  some  warm  water,  and  the  lime  will  readily  come 
off.  But  if  it  has  been  allowed  to  remain  in  the  churn  too 
long,  it  will  form  a  lime  carbonate,  and  will  be  more  difficult 
to  remove. 

Lime  is  one  of  the  best  disinfectants  and  deodorizers  that 
can  be  used  in  a  creamery.  Some  of  the  best  butter-makers 
use  it  every  day  on  all  the  wooden  utensils,  such  as  on  butter- 
workers,  churns,  etc.  Lime  can  be  used  more  advantageously 


CHURNING  AND  WASHING  BUTTER.  247 

in  American  creameries  than  it  is  to-day.  Many  creameries 
would  be  in  a  much  sweeter  and  purer  condition  if  they  were 
given  a  good  coat  of  whitewash  on  the  inside  once  a  month. 
Refrigerators,  wooden  utensils,  and  rooms  of  any  kind  can  be 
kept  in  a  good  sweet  and  pure  condition  by  whitewashing  or 
sprinkling  a  little  lime  on  them. 

WASHING  OF  BUTTER. 

Purpose  of  Washing. — The  chief  object  of  washing  butter  is 
to  remove  as  much  buttermilk  as  possible.  The  more  impure 
the  cream  is,  the  greater  is  the  importance  of  getting  the  butter 
thoroughly  washed.  In  the  winter,  when  it  is  cold,  and  the 
cream  is  in  good  condition,  some  makers  do  not  wash  the 
butter  at  all.  But  this  is  not  a  safe  method.  The  removal 
of  the  buttermilk  constituents  should  be  as  complete  as  con- 
ditions will  permit. 

Temperature  of  Wash-water. — The  temperature  of  wash- 
water  should  be  as  nearly  like  that  of  the  cream  when  churned 
as  is  consistent  with  the  other  conditions.  Extreme  and  rapid 
changes  in  temperature  should  always  be  avoided.  Occasionally 
it  is  necessary  to  use  water  that  is  colder  than  the  cream.  At 
other  times  it  is  necessary  to  use  wash-water  at  a  higher  tem- 
perature than  that  of  the  cream.  If  the  butter  churns  soft, 
do  not  use  ice-cold  wash-water  to  chill  the  butter,  as  it  has  a 
tendency  to  give  butter  a  tallowy  appearance.  Neither  should 
hard  butter  be  quickly  softened  by  using  wash-water  at  a  very 
high  temperature,  as  it  is  likely  to  cause  the  butter  to  assume 
a  greasy  and  slushy  texture.  If  it  is  necessary  to  change  the 
degree  of  hardness  of  the  butter,  change  it  gradually  by  using 
water  at  a  moderate  temperature  and  allowing  the  butter  to 
be  in  contact  with  it  a  longer  time  without  agitating  it  much. 

Unless  the  butter  is  of  very  poor  quality,  excessive  washing 
should  be  avoided.  Cold  water  is  said  to  absorb  a  considerable 
portion  of  the  flavoring  substances.  If  the  quality  of  the 
butter  is  poor,  many  of  the  undesirable  flavors  and  odors  are  re- 


248  BUTTER-MAKING. 

moved  by  excessive  washing;  while  if  the  butter  has  a  fine,  rich 
flavor,  it  should  be  retained,  and  not  extracted  by  washing 
the  butter  more  than  is  needed.  No  definite  temperature  can 
be  given,  as  the  temperature  of  wash-water  must  vary  accord- 
ing to  the  hardness  of  the  butter  when  churned. 

If  the  temperature  of  the  wash- water  is  too  high,  and  the 
churning  in  the  wash-water  is  continued  a  very  long  time,  much 
water  will  be  incorporated  in  the  butter.  If  the  butter  is  quite 
firm  in  the  first  place,  and  the  temperature  of  the  wash-water 
is  not  above  60°  F.,  there  is  not  much  danger  of  getting  too 
much  water  in  the  butter.  Rapid  changes  in  the  degree  of 
hardness  of  the  butter  in  the  presence  of  wTater  are  conducive 
to  a  high  moisture-content.  Very  soft  butter  chilled  in  very 
cold  water,  and  hard  butter  softened  in  very  warm  wash-water 
are  two  conditions  which  should  be  avoided. 

Kind  of  Wash-water  to  Use. — In  the  washing  of  butter, 
it  is  very  essential  that  water  used  should  be  the  best  obtain- 
able. The  creamery  water-supply  is  evidently  much  better 
now  than  it  was  years  ago.  Pond- wells  and  shallow  wells  are 
gradually  passing  out  of  existence,  but  there  are  yet  many 
shallow  wells  from  which  water  is  drawn  for  creamery  purposes. 
Water  from  wells  may  appear  to  be  pure,  and  yet  contain 
germs  which  are  deleterious  to  dairy  products,  and  especially 
to  the  keeping  quality  of  butter.  That  water  of  average  purity 
contains  such  germs  has  been  demonstrated  in  this  country, 
as  well  as  in  foreign  countries.  Shallow  well-water  contains 
on  an  average  about  15,000  germs  per  cubic  centimeter,  but 
Miquel  has  found  that  a  rapid  power  of  multiplication  charac- 
terizes the  bacteria  in  pure  spring-water,  while  in  impure  water 
the  multiplication  is  slower.  Water  containing  only  this  many 
germs  is,  as  a  rule,  considered  very  pure.  Most  creameries, 
however,  pump  their  water  into  a  tank  overhead  in  the  creamery, 
where  it  is  contaminated  with  bacteria  and  impurities  of  different 
kinds. 

Shallow  wells  are  usually  surrounded  with  conditions  which 
do  not  guarantee  a  creamery  pure  water  during  the  different 


CHURNING  AND   WASHING  BUTTER. 


249 


seasons  of  the  year.  In  the  spring,  when  rains  are  frequent 
and  heavy,  unwholesome  surface-water  is  likely  to  seep  in 
through  the  sides.  Such  wells  may  also  serve  as  traps  for 
small  animals.  The  presence  of  an  animal  in  the  well  is  sure 


FIG.  151. — The  shallow  barnyard  well  with  privy-vault  and  manure  heaps 
near  by.  The  water  is  likely  to  be  contaminated  from  these  any  time. 
(Farmer's  Bui.  No.  43,  U.  S.  Dept.  of  Agriculture.) 

to  cause  undesirable  odors  and  a  multitude  of  undesirable  and 
putrefactive  organisms. 

Water  from  deeply  drilled  wells,  even  if  it  is  pure  in  so  far 
as  its  germ-content  is  concerned,  is  in  many  cases  turbid  and 
sandy,  and  needs  to  go  through  a  process  of  purification  as  much 
as  does  the  shallow  well-water. 


250  BUTTER-MAKING. 


METHODS  OF  PURIFYING  WASH-WATER. 

There  are  two  practical  and  effective  methods  of  purifying 
wash-water,  viz.,  (1)  Filtration,  and  (2)  Pasteurization.  Which 
of  these  two  methods  is  the  most  practicable  and  the  most 
effective  in  the  creamery  depends  upon  the  conditions  and 
upon  the  quality  of  the  water.  In  the  case  of  water  from  deep 
wells,  which  contains  little  or  no  organic  matter,  but  at  the 
same  time  is  infested  with  undesirable  germs,  pasteurization 
is  perhaps  more  expedient.  Filtration,  if  the  same  degree  of 
thoroughness  is  to  be  reached  as  in  pasteurization,  is  a  com- 
paratively slow  process.  Pasteurization  of  wash-water  is  a 
trifle  more  expensive  than  filtration.  Wash-water  can  be 
pasteurized  at  the  same  time  that  the  churning  is  being  done, 
thus  economizing  in  time  and  fuel.  Pasteurization  is  quite 
effective  in  rendering  the  water  germ-free,  but  it  is  not  so 
effective  in  removing  any  organic  matter  or  other  tangible 
impurities  which  may  be  present.  If  the  creamery  does  not 
already  have  a  pasteurizer,  filtration  can  be  employed  very 
profitably,  and  under  average  conditions  it  will  perhaps  give 
the  best  results. 

Filtration. — Filtration  is  inexpensive,  and  is  a  very  efficient 
method  of  purifying  wash-water.  It  seems  strange  that  bacteria 
can  be  removed  from  water  by  passing  through  layers  of  sand, 
gravel,  coke,  and  charcoal,  but  such  is  the  case.  Filtration 
is  applicable  to  all  kinds  of  water;  even  if  the  water  appears 
pure,  it  is  well  to. filter  it.  Fewer  germs  and  fewer  varieties 
of  micro-organisms  are  apparently  found  in  deep  well-water 
than  is  the  case  in  water  from  surf  ace- wells;  hence  the  ferments 
which  are  present  will  have  a  free  field  for  developing  in  the 
absence  of  competing  forms.  If  a  sample  of  water  which  is 
rich  in  micro-organisms  is  violently  shaken  with  a  certain  amount 
of  charcoal,  coke,  chalk,  or  similar  substances,  and  then  left 
for  a  time  to  settle,  the  pure  layer  of  water  at  the  top  will  be 
almost  entirely  free  from  germs,  and  in  some  cases  entirely 


CHURNING  AND  WASHING  BUTTER.  251 

sterile.  It  used  to  be  thought  by  older  German  investigators 
that  these  different  filtering  substances  had  almost  miraculous 
power  of  removing  organisms  from  water. 

The  factors  which  are  to  be  considered  in  successful  filtra- 
tion are: 

(1)  Storage  capacity  for  unfiltered  water. 

(2)  Construction  of  filter-beds. 

(3)  Rate  of  filtration. 

(4)  Renewal  of  filter-beds. 

(1)  Concerning  the  storage  capacity,  nearly  all  creameries 
have  storage-tanks  overhead  in  the  creamery;    so  far  as  that 
is  concerned,  however,  filtration  can  be  successfully  carried  on 
continuously  as  well  as  intermittently. 

(2)  The  construction  of  the  filter-bed  used  in  the  experi- 
ment carried  on  at  the  Iowa  Experiment  Station,  Ames,  Iowa, 
is   as  shown  in  Fig.  153.      The    approximate    proportionate 
depth   of  each  layer  in  the  bed  is  as  follows,  beginning   at 
the  bottom: 

Two  inches  small  flint  stones;  22  inches  fine  sand;  12 
inches  fine  coke;  9  inches  charcoal;  2  inches  fine  stone  or  coarse 
gravel.  The  layer  of  fine  sand  should  not  be  less  than  15  inches. 
It  has  been  asserted  that  a  few  pieces  of  old  iron  mixed  in 
the  filter-bed  are  beneficial.  Alum,  lime,  and  copperas  have 
been  recommended  for  clarifying  and  deodorizing  very  impure 
water.  As  these  substances  are  soluble  they  should  not  be  used 
in  filter-beds,  which  are  intended  for  the  filtration  of  water 
for  potable  purposes.  The  filtering-can  was  made  from  22 
galvanized  iron.  The  height  of  can  is  48  inches;  diameter, 
18  inches.  The  bottom  of  the  can  is  slanting  towards  the 
faucet,  or  opening.  Thus  no  water  is  permitted  to  stand  on 
the  bottom  and  afford  opportunities  for  germs  to  accumulate. 
On  the  inside  are  three  plates.  One  lies  horizontally,  near  the 
bottom,  and  upon  it  the  filtering-material  rests.  Another  lies 
on  the  top  of  the  fine  sand.  Both  of  these  plates  were  per- 
forated with  many  small  holes.  Near  the  top  is  placed  a 
concave  plate  with  a  hole  near  the  center.  This  plate  directs 


252 


BUTTER-MAKING 


all  the  water  to  the  center  of  the  filter-bed,  and  thus  the  water 
gets  the  full  benefit  of  the  filtering  process.  The  total  cost  of 
this  filtering-can  when  complete  was  $11.11. 


FIG.  152.  FIG.  153. 

FIG.  152. — Filter-can:  1,  overflow;  2,  inlet  of  tap-water;  3,  outlet  of  filtered 
water. 

FIG.  153. — Cross-section  of  filter-bed  and  can:  1,  overflow;  2,  inlet;  3,  out- 
let of  filtered  water;  4,  perforated  galvanized-iron  plate;  5,  perforated 
galvanized-iron  plate;  6,  concave  galvanized-iron  plate  with  hole  in 
center. 

(3)  The  rate  of  filtration  is  necessarily  governed  by  the 
depth  of  the  filter-bed,  the  character  of  the  material  used,  and 
its  fineness.  The  water  passes  through  the  charcoal,  coke, 
and  gravel  quite  rapidly,  yet  the  substances  are  very  strong 
barriers  to  the  passage  of  micro-organisms.  The  sand  layer 
does  not  admit  of  so  rapid  filtration.  Fine  sand,  however,  is 
one  of  the  best  filtering  substances  that  can  be  had.  The  rate 
of  filtration  can  be  regulated  by  increasing  or  decreasing  the 


CHURNING  A ND  WASHING  B UTTER.  253 

depth  of  the  fine-sand  layer.  In  a  general  way,  the  slower  the 
rate  of  filtration  is,  the  more  thorough  it  is;  and,  vice  versa,  the 
more  rapid  the  rate  of  filtration,  the  more  incomplete  is  the 
removal  of  the  bacteria.  If  the  filter-bed  is  constructed  as 
described  above,  the  rate  of  filtration  will  be  about  18  gallons 
per  hour,  and  about  96%  of  all  the  germs  present  will  be  removed, 
together  with  the  impurities  present  in  suspension. 

(4)  The  filter  used  at  the  Iowa  Experiment  Station  was  in 
constant  use  for  about  three  months,  without  having  been 
changed.  At  the  end  of  this  time  it  did  as  efficient  work  as 
at  any  previous  time.  The  length  of  time  a  filter-bed  can  be 
used  without  being  changed  depends  upon  the  purity  of  the 
water  to  be  filtered,  and  also  upon  which  kind  of  filtration  _is 
used,  the  continuous  or  the  intermittent.  The  more  impure 
the  water  which  has  to  be  filtered,  the  oftener  the  filter-bed 
should  be  changed.  Whenever  the  rate  of  filtration  is  decreased 
to  such  an  extent  as  to  make  the  process  impracticable,  the 
filter-bed  should  be  taken  out  and  cleaned.  If  the  water 
to  be  filtered  is  of  average  purity,  a  change  of  the  filtering-mate- 
rial once  every  four  months  is  ordinarily  sufficient,  no  matter 
whether  continuous  or  intermittent  filtration  is  used.  A 
filter-bed  may  do  efficient  work  even  a  longer  time  than  this. 
The  same  filtering-material  can  be  used  again  providing  it  is 
thoroughly  washed  previous  to  replacing  it  in  the  filtering-can. 

Kinds  of  Filtration. — The  two  kinds  of  filtration  in  use  are 
(1)  Continuous,  and  (2)  Intermittent. 

By  the  continuous  method  of  filtration  the  inflow  of  water 
into  the  can  is  constant  during  night  and  day.  The  stream  of 
water  admitted  into  the  filter-can  is  sufficient  to  cause  the 
surface  of  the  filter-bed  to  be  covered  with  water  all  the  time. 
This  method  excludes  all  oxygen  from  the  filter-bed,  except 
that  which  is  in  solution  in  the  water. 

During  the  process  of  filtration  a  slimy  coat  is  deposited 
on  the  fine  sand.  This  seems  to  be  the  real  agent  absolutely 
necessary  in  order  to  eliminate  bacteria  by  a  process  of  filtra- 
tion. A  filter-bed  without  this  slimy  deposit  on  it  simply  takes 


254  BUTTER-MAKING. 

out  the  coarse  organic  and  inorganic  matter  held  in  suspension, 
without  removing  the  bacteria.  If  some  bacteria  are  removed 
with  the  matter  held  in  suspension,  others  are  carried  along 
from  the  filter-bed.  Owing  to  this,  a  new  filter-bed  must  be 
kept  in  operation  a  few  days  before  the  filtered  water  can  be 
considered  pure  and  ready  for  use.  The  following  table  illus- 
trates how  the  germ-content  of  water  is  decreased  as  the  process 
of  filtration  is  carried  on  during  the  first  few  days : 


Vo.  1.   Tali 
2.        ' 
3. 

.en  wh 

en  filter 

-bed  was  first  used 
had  worked  1 

"       3 

Filtered 
Water, 
Germs  per 
c.  c. 

20,000 

Un  filtered 
Tap-water, 
Germs  per 
c.  c. 

107 
118 
96 

dav 

860 

days.  . 

370 

4.        ' 

' 

t 

"       5 

" 

48 

54 

5.        ' 

1 

' 

"       7 

"    .. 

3 

73 

6.                                '                       "       9 

<  i 

5 

89 

It  will  be  seen  from  the  table  that  during  the  first  three 
days  the  filter-bed  was  in  use  the  filtered  water  contained  more 
germs  than  the  unfiltered.  Good  results  were  not  obtained 
until  the  seventh  day.  In  order  to  be  on  the  safe  side  it  is 
best  to  expose  the  filter-bed  to  continuous  filtration  for  about 
nine  days  before  the  water  is  used. 

The  slimy  coat  referred  to  above  is  formed  by  certain  germs. 
These  germs  then  constitute  the  real  agent  of  filtration.  In 
order  for  these  micro-organisms  to  do  efficient  work  oxygen 
is  essential.  Well-water  of  average  purity  contains  enough 
oxygen  in  solution  without  employing  an  intermittent  process  of 
filtration,  and  consequently  for  creamery  purposes  the  con- 
tinuous method  of  filtration  is  to  be  recommended. 

Intermittent. — The  intermittent  process  of  filtration  is  used 
where  comparatively  impure  water  is  being  purified,  such  as 
in  purifying  \vater  for  large  cities.  If  the  continuous  process 
of  filtration  were  employed  in  such  instances,  the  filtered 
water  would  not  be  free  from  germs,  due  to  the  fact  that  impure 
river-water  does  not  carry  enough  oxygen  in  solution  to  supply 
the  germs  which  form  the  real  filtering  agency. 


CHURNING  AND  WASHING  BUTTER.  255 

If  the  intermittent  process  is  used,  the  first  water  filtered 
after  the  intervening  period  should  not  be  used.  During  the 
intermission,  or  during  the  time  that  the  water  is  shut  off, 
germs  develop  and  come  through  the  filter-bed  with  the  water 
that  is  filtered. 

Advantages  of  Purifying  Wash-water  for  Butter. — The  chief 
advantage  of  purifying  wash-water  for  butter  is  that  the  keeping 
quality  of  the  butter  is  improved,  and  if  the  proper  skill  and 
care  have  been  applied  in  the  other  steps  of  manufacture,  a  pure 
sanitary  product  is  obtained.  The  sanitary  efficiency  reached 
by  purifying  the  wash-water  constitutes  no  small  consideration. 
Germs  producing  contagious  diseases  are  thus  checked  from 
spreading. 


CHAPTER  XVII. 

SALTING  AND  WORKING  OF  BUTTER. 

Objects  of  Salting. — The  chief  objects  of  salting  are:  (1) 
to  impart  a  desirable  flavor;  (2)  to  increase  the  keeping  quality 
of  butter;  and  (3)  to  facilitate  the  removal  of  buttermilk. 

Amount  of  Salt  to  Use  to  Produce  Proper  Flavor. — The  proper 
amount  of  salt  to  use  in  order  to  impart  a  desirable  flavor 
depends  chiefly  upon  the  market.  Some  consumers  prefer  a 
medium  high  salt-content  in  butter;  others,  again,  like  butter 
which  contains  very  little  salt.  The  English  market  demands 
rather  light-salted  butter.  In  fact,  this  is  the  case  with  prac- 
tically all  European  markets.  American  markets,  as  a  rule, 
demand  comparatively  high-salted  butter,  as  much  as  will 
properly  dissolve  in  the  butter.  Parisian  markets  .and  some 
markets  in  southern  Germany  require  no  salt  in  it  at  all.  The 
salt-content  of  butter  may  vary  between  nothing  and  4%. 
Butter  containing  as  much  as  4%  salt  is,  as  a  rule,  too  highly 
salted.  When  it  contains  this  much  salt,  part  of  the  salt  is 
usually  present  in  an  undissolved  condition.  Those  who  like 
good  butter  prefer  butter  that  contains  the  salt  thoroughly 
dissolved  and  well  distributed. 

The  amount  of  salt  to  be  added  should  be  based  upon  the 
least  variable  factor.  Some  creamerymen  measure  the  amount 
of  salt  according  to  the  amount  of  cream  in^the  churn.  While 
the  box-churn  and  Mason  butter-worker  were  being  used,  many 
makers  preferred  to  weigh  the  butter  as  it  was  transferred  from 
the  churn  to  the  worker.  The  method  mostly  in  use  now,  and  to 
be  recommended,  is  to  base  the  amount  of  salt  upon  the  number 
of  pounds  of  fat.  The  amount  of  salt  to  use  per  pound  of  fat 

256 


SALTING  AND  WORKING  OF  BUTTER.  257 

varies,  therefore,  according  to  the  conditions  mentioned  below, 
and  also  according  to  local  conditions.  Usually  from  half 
an  ounce  to  one  and  a  half  ounces  of  salt  per  pound  of  butter- 
fat  is  most  suitable.  In  whole-milk  creameries  the  salt  is 
often  estimated  per  hundredweight  or  per  thousand  pounds  of 
milk. 

To  get  the  butter  salted  uniformly  from  day  to  day  is  very 
important,  as  a  small  variation  in  the  salt-content  has  a  greater 
effect  upon  the  quality  of  butter  than  has  a  small  variation 
in  any  of  the  other  butter  constituents.  A  variation  of  1% 
to  2%  in  the  salt-content  can  very  easily  be  detected  by  the 
consumer,  while  that  much  variation  in  any  one  of  the  other 
constituents  could  not  be  readily  noticed. 

The  conditions  upon  which  the  proper  amount  of  salt 
depend  are:  First,  the  amount  and  condition  of  moisture  in 
the  butter  at  the  time  the  salt  is  added.  If  there  is  a  great 
deal  of  loose  moisture  in  the  butter,  more  salt  is  necessary. 
This  is  due  to  the  fact  that  the  salt  will  go  into  solution  in  the 
water  and  be  expressed  during  working.  Secondly,  it  depends 
upon  the  ^amount  of  working  the  butter  receives,  and  at  what 
time  the  bulk  of  working  is  done,  after  the  salt  has  been  added. 
If  the  butter  is  medium  firm,  moisture  in  the  form  of  brine 
is  being  expressed  during  the  working.  Consequently,  the  more 
butter  is  worked,  up  to  a  certain  limit,  the  more  brine  is  being 
expressed,  and  the  more  salt  should  be  added  to  the  butter. 
Thirdly,  the  amount  of  salt  to  add  depends  also  upon  the  size 
of  the  butter  granules  at  the  time  the  salt  is  being  added,  and 
the  hardness  and  softness  of  the  butter.  If  the  granules  are 
very  small  and  quite  hard,  they  take  salt  with  difficulty.  The 
salt  attracts  also  more  moisture  from  these  small  granules  than 
from  larger  ones,  which  will  escape  in  the  form  of  brine. 
If  the  butter  is  present  in  a  rather  soft,  lumpy  condition  at 
the  time  the  salt  is  added,  and  there  is  no  water  in  the  churn, 
very  little  salt  is  wasted  in  the  form  of  brine,  consequently 
less  salt  is  necessary  in  the  first  place. 

It  is  undoubtedly  due  to  these  facts   that  the  salt-content 


258  BUTTER-MAKING. 

and  the  condition  of  salt  in  butter  vary  so  much  at  the  different 
creameries;  they  even  vary  considerably  from  one  churning 
to  another  at  the  same  creamery.  If  conditions  are  uniform 
in  the  creamery  from  day  to  day,  the  amount  of  salt  to  add 
to  butter,  and  the  amount  of  salt  retained  in  the  butter  when 
finished,  will  be  comparatively  uniform. 

It  should  be  mentioned  in  this  connection  that  butter  made 
from  very  good  cream  should  not  be  salted  too  heavily.  Butter 
made  from  a  rather  poor  quality  of  cream  may  be  salted  corre- 
spondingly heavier.  This  is  due  to  the  fact  that  the  heavy 
salty  taste  covers  some  of  the  undesirable  flavors  in  the  butter. 
If  the  butter-flavors  are  good,  they  should  not  be  hidden  by 
a  heavy  salty  taste.  If  the  butter-flavors  are  poor,  then  it 
may  be  policy  to  partially  cover  them  up  with  a  medium-heavy 
salty  flavor. 

Effects  of  Salt  upon  Keeping  Properties. — That  salt  is  anti- 
septic is  no  longer  a  doubt.  It  has  been  demonstrated  in 
laboratory  work  with  butter  that  the  growth  of  certain  germs, 
isolated  from  butter,  can  be  completely  checked  by  the  addi- 
tion of  a  certain  amount  of  salt  to  the  medium  in  which  they 
are  inoculated.  Bouska  *  found  that  a  yeast  isolated  from 
butter  showed  luxuriant  growth  in  a  medium  containing  2% 
of  salt  in  forty-eight  hours,  and  only  a  trace  in  4%  of  salt. 
The  same  germ  showed  only  a  trace  of  growth  in  a  6%  salt 
medium  after  five  days. 

The  ordinary  bread-mould,  Penicillium  ylaucum,  was  iso- 
lated from  butter  and  showed  noticeable  growth  in  a  9%  Salt 
medium  in  two  days,  and  only  a  trace  in  a  10%  solution  during 
the  same  time.  A  spore-bearing  bacillus  isolated  from  butter 
produced  only  a  trace  of  growth  in  a  4(/<  salt  medium.  No 
growth  occurred  at  all  in  a  medium  containing  6%  of  salt. 
Another  gas-producing  organism  was  also  isolated  from  butter 
and  only  a  weakened  growth  was  produced  in  a  medium  con- 
taining 4%  of  salt. 

*  Iowa  Ex.  Sta.,  Bui.  80. 


SALTING  AND  WORKING  OF  BUTTER.  259 

If  it  were  practicable  and  consistent  with  the  demand  of  the 
consumers,  so  far  as  the  keeping  properties  of  butter  is  con- 
cerned, it  would  be  advisable  to  salt  butter  as  highly  as  6%. 
This  much  salt  would  tend  to  a  large  extent  to  check  deterio- 
ration of  the  butter  due  to  bacterial  growth. 

That  salt  promotes  the  keeping  quality  of  butter  has  also 
been  demonstrated  in  a  practical  way  during  the  Iowa  Educa- 
tional Contest  in  1903.  Fifty  samples  of  butter  containing  2J% 
or  more  of  salt  were  scored  off  in  New  York,  on  an  average, 
2.38  points,  while  the  remaining  171  samples  containing  less 
than  2|%  salt  were  scored  off  3.54  points  on  an  average;  a 
difference  in  favor  of  the  keeping  quality  of  high-salted  butter 
of  1.16  points.  Most  American  markets  demand  a  salt-content 
of  about  2A%  in  the  finished  product. 

Salt  Facilitates  the  Removal  of  Buttermilk. — That  salt 
facilitates  the  removal  of  buttermilk  can  easily  be  demon- 
strated by  observing  the  escape  of  buttermilk  from  the  butter 
immediately  after  the  salt  has  been  added  and  mixed  with  the 
butter.  The  first  effect  of  salt  when  added  to  the  butter  is  to 
precipitate  the  curd  in  the  buttermilk.  This  precipitation  is 
greater  when  a  large  amount  of  salt  is  added  than  when  only 
a  small  amount  is  added.  The  precipitation  of  the  casein  in 
the  buttermilk  sets  free  the  remainder  of  the  buttermilk  con- 
stituents; that  is,  when  the  casein  is  precipitated,  the  whey 
part  assumes  a  more  fluid  condition  and  escapes,  and  the  butter 
retains  a  portion  of  the  curd.  Owing  to  this  action  of  the 
salt,  it  is  essential  that  the  butter  should  be  as  completely 
washed  as  possible,  as  otherwise  it  will  retain  an  excessive 
amount  of  curd.  The  butter  acts  in  a  manner  somewhat 
similar  to  a  filter  in  removing  a  part  of  the  curd  from  the  other 
buttermilk  constituents. 

Salt  in  Relation  to  Water  in  Butter. — Experiment  has  dem- 
onstrated that  pure  fat  is  not  a  salt-dissolving  substance. 
Owing  to  this  fact  the  only  salt-dissolving  substance  in  butter 
is  water.  As  water  will  hold  only  a  certain  amount  of  salt 
in  solution,  it  becomes  evident  that  the  amount  of  salt  which 


260 


BUTTER-MAKING. 


can  be  properly  incorporated  in  butter  depends  upon  the  amount 
of  moisture  present. 

The  amount  of  salt  which  water  will  hold  in  solution  at 
different  temperatures  varies  somewhat  according  to  differ- 
ent investigators.  According  to  Gerlach  *  water  will  dissolve 
35.94%  salt  at  58°  F.  This  is  approximately  the  temperature 
at  which  salt  is  worked  into  butter.  Theoretically,  butter 
containing  15%  of  water  should  be  able  to  properly  dissolve 
5.4%  of  salt.  Butter  containing  13%  of  water  should  be  able 


FIG.  154. — Action  of  salt  solutions  of  different  strength  on  the  proteids  of 
buttermilk.     (Bui.  263,  Gen.,  N.  Y.) 

to  properly  dissolve  4.68%  of  salt,  and  butter  containing  10% 
of  water  should  be  able  to  dissolve  properly  3.6%  of  salt,  etc. 
According  to  experiments  conducted  at  the  Iowa  Experiment 
Station  the  maximum  per  cent  of  pure  salt  (NaCl)  that  could 
be  properly  dissolved  in  water  of  butter  containing  16.92% 
of  moisture,  when  worked  18  revolutions  at  intervals  during 
two  hours,  was  16.57%.  When  butter  was  worked  the  same 
number  of  revolutions  at  intervals,  and  was  allowed  to  dissolve 

*  Kemiker-Kalender,  p.  219. 


SALTING  AND  WORKING  OF  BUTTER.  261 

only  one  hour,  the  amount  of  pure  salt  (NaCl)  that  was  dissolved 
in  the  water  of  the  butter  containing  11.58%  moisture  was 
14.09%.  This  undoubtedly  will  vary  with  different  brands 
of  salt. 

It  will  thus  be  seen  that  the  property  of  water  to  take  up 
salt  is  seemingly  lessened  when  the  water  is  present  in  a  state 
of  minute  division,  as  it  is  in  butter.  In  the  first  instance 
quoted  the  butter  completely  dissolved  about  2.7%  of  pure 


FIG.  155. — Volumes  of  the  same  weight  of  salt  of  various  brands. 
(Bui.  74,  Wis.) 

salt;    and  in  the  second  instance  it  dissolved  only  about  2% 
during  one  hour. 

Condition  of  Salt  when  Added. — The  condition  of  salt  when 
added  is  a  very  important  question  to  consider  in  order  to  get 
enough  salt  properly  incorporated.  The  amount  of  influence 
which  the  quality  of  the  salt  has  upon  flavor  has  recently  been 
a  subject  of  attractive  interest,  for  many  of  our  best  butter- 
judges  have  made  the  charge  that  certain  undesirable  flavors 
in  butter  can  be  traced  to  the  use  of  a  poor  quality  of  salt. 
This  assumed  effect  upon  the  quality  of  the  butter  can  only 
be  remedied  by  stopping  the  use  of  impure  salt.  The  chief 
undesirable  and  impure  constituent  present  in  salt  is  magne- 


262  BUTTER-MAKING. 

slum  chloride.  It  is  known  positively  that  the  presence  of  this 
substance  in  salt,  even  to  a  small  extent,  imparts  a  bitter  flavor 
to  butter.  Salt  containing  a  large  amount  of  this  and  other 
impurities  also  absorbs  moisture  from  the  air  more  readily 
than  does  pure  salt.  According  *  to  analysis  of  the  best  dairy 
salt  in  use  in  Denmark,  the  composition  is  as  follows : 

Pure  salt 97.49 

Magnesium  chloride 18 

Gypsum 05 

Sodium  sulphate 21 

Water.  .  2.07 


100.00 

The  purest  American  dairy  salt  has  the  following  composi- 
tion :  | 

Pure  salt  (NaCl) 99. 18 

Magnesium  chloride  (MgCl2) 05 

Gypsum  (calcium  sulphate,  CaS04) , .  54 

Calcium  chloride  (CaCk) 19 

Insoluble  matter 03 

Moisture..  .01 


100.00 

In  order  to  judge  the  quality  of  salt  the  butter-maker 
cannot  rely  on  the  chemical  analysis  for  a  detection  of  im- 
purities, but  must  judge  the  quality  from  its  appearance, 
flavor,  and  odor.  Good  dairy  salt  does  not  have  a  dark-bluish, 
coarse,  granulated  appearance,  but  a  clean,  white,  silky  look, 
and  should  dissolve  quickly.  Salt  should  be  kept  in  a  clean 
dry  place  free  from  odor. 


*  Boggild,  Maolkeribruget,  Denmark, 
t  Bui.  No.  74,  Wis.,  by  F.  W.  Woll. 


SALTING  AND  WORKING  OF  BUTTER.  263 

Gritty  Butter. — "Gritty  butter"  is  a  familiar  phrase  used 
by  expert  butter-scorers  to  indicate  that  part  of  the  salt  is 
present  in  an  undissolved  condition.  To  most  consumers  this 
condition  of  the  salt  in  butter  is  objectionable.  When  properly 
incorporated,  salt  should  be  present  in  the  form  of  a  solution 
in  the  butter.  The  gritty  condition  of  the  salt  in  butter  may 
be  due  to  (1)  poor  condition  of  the  salt  before  it  is  added  to 
the  butter;  (2)  adding  so  much  salt  that  it  cannot  be  dis- 
solved by  the  water  in  the  butter.  The  maximum  amount 
of  salt  that  butter  will  dissolve  depends  upon  the  amount  of 
moisture  present.  The  maximum  amount  of  moisture  per- 
missible in  butter,  as  limited  by  law,  is  16%.  The  condition 
of  the  water  in  butter  prevents  the  water  from  being  saturated 
with  salt  during  the  comparatively  short  time  allowed  for  salt 
to  dissolve  during  the  manufacture  of  butter.  (3)  Insufficient 
working.  If  the  butter  is  not  worked  enough  to  distribute 
the  salt  evenly,  some  portion  of  the  butter  will  contain  more 
than  the  other  portions.  The  portion  that  contains  the  excess 
of  salt  does  not  have  enough  moisture  to  dissolve  the  salt; 
while  if  the  salt  had  been  evenly  distributed  in  the  butter,  all 
the  salt  would  have  been  properly  dissolved.  When  gritty 
butter  is  caused  by  insufficient  working,  it  usually  mottles. 

Mottled  Butter.— Mottled  butter  is  butter  which  is  uneven 
in  color.  This  unevenness  in  color  may  be  due  to  several 
different  causes.  It  may  be  due  to  specks  of  curd  (speckled 
butter),  and  it  may  be  due  to  certain  organisms  (dappled 
butter).  These  causes  of  mottled  butter  are  not  very  com- 
mon in  factories  where  the  manufacture  of  butter  is  properly 
carried  on. 

The  most  common  fault  of  mottled  butter  is  the  improper 
incorporation  of  salt  and  the  presence  of  an  excessive  amount 
of  buttermilk.  Mottled  butter  caused  in  this  way  is  com- 
mon. It  would  be  of  much  commercial  importance  if  it  were 
possible  to  prevent  its  occurrence.  In  case  all  the  water 
had  been  saturated  with  salt,  and  there  is  still  undissolved 
salt  left,  then  the  granular  or  undissolved  salt  will  cause  no 


264  BUTTER-MAKING. 

mottles.  The  most  important  thing  to  observe  in  order  to 
prevent  mottles  is:  (1)  to  have  the  buttermilk  well  washed 
out;  (2)  to  have  the  salt  thoroughly  dissolved;  and  (3)  to 
have  the  brine  properly  distributed. 

Recent  work  by  Drs.  Van  Slyke  and  Hart  show  that  if  the 
proteids  are  thoroughly  washed  from  the  butter,  mottles  cannot 
be  produced,  no  matter  how  unevenly  the  salt  is  distributed. 
Complete  removal  of  the  buttermilk  by  washing  is  one  of  the 
essentials  in  order  to  prevent  mottles  in  butter. 

The  mottles  caused  by  improper  incorporation  of  salt  assume 
two  different  forms,  viz.,  mottles  proper,  and  wavy  butter. 
As  has  been  mentioned  before,  the  mottles  result  from  un- 
dissolved  salt.  Whenever  there  is  undissolved  granular  salt 
present,  the  moisture  is  attracted  and  the  color  deepened  at 
that  particular  place.  In  case  the  water  has  already  been 
saturated  with  salt,  there  is  no  danger  of  mottles,  no  matter 
how  much  gritty  salt  is  present. 

Wavy  butter  is  caused  by  an  uneven  distribution  of  the 
brine.  If  a  little  salt  is  added  to  the  butter  and  dissolved 
without  working  the  butter  sufficiently,  the  salt  will  go  into 
solution  in  certain  portions  of  the  water.  This  water  contain- 
ing the  greatest  amount  of  salt  will  produce  a  high  color  in 
certain  portions  of  the  butter,  while  the  portion  containing 
water  with  less  salt  will  have  a  lighter  color,  thus  causing 
streaks  in  the  butter. 

In  case  butter  has  become  mottled  on  standing,  the  mottles 
can  be  entirely  eradicated  by  reworking  the  butter.  Though 
some  of  the  moisture  is  lost  during  this  reworking  process, 
it  is  usually  advisable  to  rework  the  butter  rather  than  to 
place  it  on  the  market  in  a  badly  mottled  condition.  The 
mottles  should,  however,  be  prevented  rather  than  cured. 
This  can  be  done  by  sufficient  working  while  the  butter  is  in 
proper  condition,  and  at  the  proper  time. 

Brine-salting. — Brine-salting  is  not  as  a  rule  practiced  in 
creameries.  It  is  too  expensive  a  method  of  salting,  and  also 
too  laborious.  By  salting  butter  with  brine  it  is  hardly  possible 


SALTING  AND  WORKING  OF  BUTTER.  265 

to  get  in  salt  enough  to  suit  the  American  butter  markets, 
2%  being  about  the  maximum  amount  of  salt  that  can  be 
incorporated  by  the  brine  method. 

In  some  instances,  brine-salting  has  been  recommended.  If 
a  light  mild  taste  is  desired,  the  brine  method  may  give  good 
results.  The  greatest  advantages  of  brine-salting  are  that 
mottles  in  butter  are  practically  avoided,  and  that  the  over- 
run is  usually  increased  a  trifle.  Especially  is  this  so  if  the 
temperature  of  the  brine  is  medium  high  when  added  to  the 
butter.  In  order  to  get  enough  salt  (2%)  into  the  butter  by 
the  brine  method,  it  is  necessary  to  churn  it  considerably  in 
the  brine  and  to  use  two  sets  of  brine.  When  brine  is  first 
added  the  butter  already  contains  considerable  water.  This 
water  practically  has  to  be  replaced  by  brine.  This  is  difficult 
to  do,  especially  if  the  butter  has  been  overchurned  a  trifle. 

By  churning  the  butter  in  the  first  set  of  brine,  the  brine 
will  soon  become  diluted  to  such  an  extent  that  it  will  impart 
but  little  saltiness  to  the  butter.  For  this  reason  this  first 
set  of  brine  should  be  removed  and  another  one  added.  Then 
churn  again  in  this  brine.  This  last  set  of  brine  will  have 
very  little  curd  in  it,  and  can  be  saved  until  the  following  day 
and  then  used  as  the  first  set  of  brine.  This  first  set  of  brine 
may  be  used  each  day  for  soaking  tubs. 

It  is  essential  to  leave  the  brine  on  the  butter  for  from  five 
to  fifteen  minutes.  Churning  excessively  in  the  brine,  espe- 
cially if  butter  is  medium  soft,  will  cause  too  much  water  to 
be  incorporated  in  the  butter.  After  the  butter  has  been  ex- 
posed to  the  second  set  of  brine  the  proper  length  of  time,  it 
should  be  drawn  off  and  the  butter  worked  in  the  usual  manner. 
Less  working  is  usually  given  to  butter  which  has  been  salted 
by  the  brine  method.  It  should  be  worked  enough  to  dis- 
tribute the  brine  evenly  in  the  butter,  and  to  bring  the  butter 
into  a  compact  form.  If  the  butter  salted  by  the  brine  method 
is  not  worked  sufficiently,  it  will  after  standing  become  streaky 
in  color. 


266  BUTTER-MAKING. 


WORKING  OF  BUTTER. 

Objects. — The  objects  of  working  butter  are: 

(1)  To  distribute  the  salt  and  brine  evenly  in  the  butter. 
The  number  of  revolutions  in  the  churn  necessary  to  accom- 
plish this  will  vary  somewhat  according  to  the  conditions  of 
the  butter,  and  according  to  the  kind  of  butter-workers  em- 
ployed. If  the  butter  is  of  medium  firmness,  about  12  revolu- 
tions in  the  Victor  Combined  Churn  will  usually  distribute  the 
salt  properly,  providing  the  working  is  well  distributed  over  the 
working  period.  It  used  to  be,  and  is  still,  the  practice  in 
creameries  to  add  the  salt  while  the  butter  is  in  a  hard  granular 
condition,  and  then  rotate  the  churn  several  times  in  slow  gear 
without  putting  the  workers  in  gear.  This  is  done  in  order 
to  mix  the  salt  thoroughly  without  working.  Then  it  is  allowed 
to  stand  for  five  or  ten  minutes,  then  worked  about  four  revolu- 
tions and  allowed  to  stand  a  little  while  again,  then  the  working 
is  completed  by  allowing  the  churn  to  revolve  four  or  five  times 
more,  or  as  many  as  is  deemed  necessary  to  bring  the  butter  into 
proper  condition. 

It  has,  however,  been  demonstrated  that  it  is  not  advisable 
to  add  the  salt  while. the  butter  is  in  this  hard  granular  form. 
The  butter  should  be  united  into  larger  irregular  granules  before 
the  salt  is  added.  If  the  salt  is  added  to  the  butter  in  a  more 
or  less  gathered  condition,  then  the  workers  should  be  put  in 
gear  at  once,  for  otherwise  the  salt  will  be  scattered  on  the 
inside  of  the  churn.  Butter  can  be  worked  three  or  four  revolu- 
tions and  then  allowed  to  stand  until  the  salt  is  almost  dissolved, 
at  which  time  the  working  can  be  completed  by  revolving 
the  chum  four  or  five  revolutions  more.  Some  prefer  to  work 
a  little  more  than  ten  revolutions  in  order  to  be  sure  that  the 
salt  has  been  evenly  distributed. 

If  the  Disbrow  churn  is  being  used,  it  is  necessary  to  work 
the  butter  a  greater  number  of  revolutions  than  that  recom- 
mended when  the  Victor  churn  is  used.  In  the  Victor  churn 


SALTING  AND  WORKING  OF  BUTTER. 


267 


the  butter  is  virtually  worked  twice  at  every  revolution,  \vhile 
in  the  Disbrow  churn  the  butter  is  only  worked  once  for  about 
three-quarters  of  a  revolution.  From  sixteen  to  twenty  revolu- 
tions of  the  Disbrow  churn  usually  mixes  the  salt  with  the  butter 
properly.  It  is  impossible  to  state  exactly  the  number  of  revo- 
lutions butter  should  be  worked,  as  it  varies  according  to  differ- 
ent conditions. 

(2)  Working  the  butter  is  done  in  order  to  bring  it  into  a 
compact  form.    "When  butter  is  soft  it  usually  gathers,  but 


FIG.  156. — The  table  butter-worker. 

if  it  is  present  in  the  firm  granular  condition,  which  condition 
results  from  churning  thin  cream  and  washing  the  butter  in 
cold  water,  it  is  more  or  less  difficult  to  get  the  little  granules 
together.  More  working  is  necessary  when  the  butter  is  in 
such  a  condition. 

(3)  The  working  of  butter  is  also  done  in  order  to  express 
an  excessive  amount  of  buttermilk  or  water.    By  adding  salt 


268  BUTTER-MAKING. 

and  then  working  the  butter,  the  excess  of  buttermilk  is  largely 
eliminated.  Especially  is  this  so  when  the  butter  is  in  a  medium 
firm  condition.  Working  is  also  effective  in  removing  water 
from  the  butter. 

In  the  manufacture  of  process  butter,  excessive  working 
while  the  butter  is  in  a  firm  condition  is  now  resorted  to. 
Before  the  national  law,  which  limits  the  moisture  content  of 
butter  to  16%,  went  into  effect,  process  butter  usually  con- 
tained more  than  16%  water;  but  now  the  moisture-content 
of  this  kind  of  butter  is  largely  controlled  by  working  it  in  the 
absence  of  water  while  it  is  in  a  firm  condition. 


V- 

»F  THE 

UNIVERSITY* 


CHAPTER  XVIII. 
PACKING  AND  MARKETING  BUTTER. 

Kind  of  Package  to  Use. — For  creamery  purposes  the  60- 
pound  ash  tubs  are  customarily  used.  The  package,  of  course, 
varies  according  to  different  markets.  In  case  that  butter  is 
made  on  a  small  scale,  such  as  on  the  farm,  earthen  crocks  give 
good  satisfaction.  There  is  no  other  package  that  gives  so 
good  results  as  the  earthen  jars,  when  viewed  from  a  stand- 
point of  good  keeping  quality  of  the  butter.  The  objec- 
tion to  earthen  jars  or  crocks  is  that  they  are  heavy  and  easily 
broken  during  transportation.  It  is  undoubtedly  on  this 
account  that  earthenware  is  not  used  more  for  the  packing  of 
butter. 

There  are  two  kinds  of  tubs  chiefly  used  in  creameries,  viz., 
the  ash  tub,  and  the  spruce  tubs.  These  tubs  are  made  in 
different  sizes,  10-lb.,  20-lb.,  30-lb.,  and  60-lb.  The  60-lb. 
ash  tub  is  used  nearly  altogether  in  creameries  that  pack  butter 
on  a  large  scale.  When  smaller  amounts  of  butter  are  being 
packed,  usually  the  smaller  spruce  tubs  are  employed.  Square 
boxes  are  used  also  to  some  extent.  They  are  used  more  in 
some  of  the  Eastern  States,  but  very  little  in  the  West  and 
Central  West. 

During  the  fall  and  winter  when  the  milk-supply  is  rather 
low,  many  creameries  print  all  the  butter.  Most  of  the  com- 
mission firms  will  pay  about  a  cent  more  per  pound  for  butter 
when  it  is  put  up  in  pound  prints  and  wrapped  neatly  in  parch- 
ment paper.  The  wrapper  should  bear  the  name  of  the  manu- 
facturer or  the  name  of  the  creamery.  If  the  quality  of  the 

269 


PACKING  AND  MARKETING  BUTTER.  271 

"butter  is  good,  it  will  take  but  a  short  time  for  the  consumers 
to  become  familiar  with  that  particular  brand.  It  is  essential, 
however,  to  consider  the  cost  of  printing  the  butter  and  the 
losses  in  printing.  Some  little  waste  of  butter  accompanies 
the  printing  process.  Besides  this,  if  the  butter  is  firm,  as  it 
usually  is  in  order  to  have  the  prints  assume  the  proper  shape, 
there  is  a  loss  of  some  moisture. 

Preparation  of  Tubs. — If  tubs  are  stored  in  a  damp  room, 
they  are  likely  to  mould  in  a  short  time.  Occasionally  tubs 
are  in  a  mouldy  condition  when  they  come  from  the  factory 
or  creamery  supply-house.  The  mould  that  forms  on  the  inside 
of  the  tub  when  standing  in  a  damp  place  is  very  conspicuous. 
In  many  instances  the  tubs  are  also  .cracked.  This  is  due 
chiefly  to  the  tubs  becoming  dry,  and  in  some  instances  is  due 
to  the  use  of  imperfect  material  in  the  manufacture  of  the  tub. 
Butter-tubs  should  not  be  made  from  damp,  unseasoned,  and 
partly  decayed  wood,  as  they  are  likely  to  impart  to  the  butter 
more  of  the  woody  odors  than  do  those  made  from  sound, 
well-matured  wood. 

In  order  to  kill  all  the  moulds  which  may  be  present  in  the 
tub,  and  to  close  the  cracks,  so  as  to  make  the  tub  practically 
air-tight,  it  is  essential  that  the  tub  should  undergo  some  process 
of  preparation  before  the  butter  is  packed  into  it.  There  is  a 
single  substance  which  will  destroy  the  germs,  moulds,  and  also 
close  smaller  openings  in  the  tubs,  viz.,  a  saturated  solution  of 
brine.  As  a  rule  this  gives  good  results.  The  day  previous  to 
the  packing  of  the  butter,  the  tubs  should  be  filled  with  satu- 
rated brine,  and  allowed  to  stand  and  soak  until  the  following 
day.  The  paper-linings  and  circles  should  also  be  soaked  in 
the  same  brine  before  they  are  used.  It  is  a  good  plan  to  have 
the  brine  lukewarm,  although  cold  brine  will  answer  the  pur- 
pose. Just  previous  to  using,  pour  out  the  brine,  wash  the  tubs 
thoroughly,  then  scald  them,  by  putting  them  into  scalding- 
hot  water  or  over  a  steam-jet.  Cool  off  the  tubs  by  filling  them 
with  cold  water;  when  cooled,  pour  out  the  water,  line  them, 
and  they  are  ready  for  use.  The  covers  should  be  on  while  they 


272 


BUTTER-MAKING. 


are  soaking.    This  prevents  the  tubs  from  warping  and  getting 
out  of  shape. 

By  soaking  the  tubs  in  brine  and  scalding  as  above,  if 
thoroughly  done,  there  is  little  danger  of  getting  moulds  in 
the  butter.  Some  recommend  the  soaking  of  the  tubs  in  brine 
only,  without  scalding;  others  recommend  the  scalding  without 
soaking  in  brine.  The  chief  difficulty  with  scalding  the  tubs 


FIG.  158.— Elgin  style  butter- 
tub. 


FIG.    159.— Bradley 
butter-boxes. 


without  soaking  is  that  when  wooden  tubs  are  exposed  to  such 
sudden  heat  they  usually  warp.  The  hoops  are  also  likely  to 
burst,  and  if  this  method  is  employed  alone,  many  of  the  tubs 
will  be  rendered  valueless  owing  to  the  bursting  of  the  hoops. 
If  the  tub  is  gradually  soaked  in  brine  first,  heat  may  be  applied 
afterwards  with  little  or  no  injury  to  the  tub.  Owing  to  the 
many  complaints  of  mouldy  butter,  especially  during  the 
summer,  several  other  methods  of  preparing  tubs  have  been 
recommended.  In  following  out  the  above  method  many  makers 


PACKING  AND  MARKETING  BUTTER.  273 

omit  to  use  concentrated  brine.  If  the  brine  is  weak,  then,  of 
course,  it  will  have  little  or  no  effect  upon  the  moulds;  but 
if  the  brine  is  saturated,  the  wood  will  become  saturated  with 
brine  and  prevent  the  growth  of  mould  during  the  trans- 
portation of  the  butter.  Moulds  usually  start  to  grow  on  the 
inside  of  the  tub,  next  to  the  butter. 

Some  of  the  other  methods  recommended  for  the  prepara- 
tion of  tubs  are:  (1)  Paraffining.  This  is  accomplished  by 
melting  the  paraffin,  then  using  a  soft  brush  with  which  to 
spread  the  liquid  paraffin  all  over  the  inside  of  the  tub.  After 
the  liquid  paraffin  has  been  applied  and  cooled,  it  will  solidify, 
and  a  thin  layer  of  paraffin  will  cover  the  inside  of  the  tub. 
(2)  The  second  method  is  to  soak  the  tubs  in  brine  containing 
from  2%  to  3%  of  formalin  (40%  formaldehyde  solution); 
about  three  ounces  of  formalin  to  each  gallon  of  brine  is  about 
the  proper  proportion. 

Special  efforts  should  be  made  towards  having  the  package 
appear  as  neat  as  possible.  They  should  be  clean,  and  the  cover 
should  fit  well.  After  the  tub  has  been  washed,  lined,  and 
otherwise  prepared,  it  should  be  weighed,  and  the  weight  of  the 
tub  marked  on  the  outside. 

Packing  of  Butter. — The  packing  of  butter  should  be  con- 
ducted under  as  favorable  conditions  as  possible.  Before  mak- 
ing use  of  the  butter-ladles  they  should  be  scalded  and  then 
cooled  off  in  cold  water.  This  prevents  the  butter  from  sticking 
to  them,  and  also  cleanses  them  from  dust  and  germs  which 
may  have  lodged  on  them.  When  the  butter  is  being  transferred 
from  the  churn  into  the  tub,  it  should  be  firmly  packed.  That 
is,  there  should  be  no  holes  near  the  bottom  and  sides  of  the 
butter  in  the  tub.  When  the  butter  arrives  on  the  market 
it  is  sometimes  turned  out  of  the  tub  (stripped).  If  it  has 
not  been  firmly  packed,  the  butter  will  be  filled  with  holes 
on  the  sides  and  show  an  unattractive  appearance.  Besides 
this,  if  there  are  any  holes  in  the  butter,  the  moisture  and  air 
will  gather  there.  This  gathered  brine  at  time  causes  a  change 
in  color  on  the  surface  of  the  butter  to  which  the  brine  was 


274 


BUTTER-MAKING. 


exposed.  The  tubs  should  be  well  filled.  Any  open  spaces 
left  in  the  butter  permit  the  circulation  of  air,  and  the  butter 
is  more  likely  to  absorb  the  woody  odors  from  the  tub. 


Folded. 

FIG.  160.— The  Eureka  hand  FIG.  161.— Butter  cartons, 

butter-printer. 

Iii  the  preparation  of  the  tub?,  many  of  these  woody  odors 
are  eliminated,  but  it  is  impossible  to  remove  all  of  them.  The 
heat  when  applied  to  the  tub  opens  up  the  pores  of  the  wood 
and  causes  the  volatile  woody  odors  to  pass  off  with  the  escaping 
steam.  When  the  wood  is  removed  from  the  influence  of  the 
steam,  the  pores  again  close,  or  contract,  and  in  that  way  most 
of  the  woody  odors  are  removed,  at  least  from  the  inner  surface 
of  the  tub.  The  remaining  woody  odors  should  not  be  allowed 
to  circulate  inwardly  through  the  butter  by  allowing  empty 
spaces  inside  the  tub.  The  top  surface  of  the  butter  can 
be  made  to  appear  smooth  and  full  by  filling  the  tub  a  little 
more  than  full  of  butter,  and^then  cutting  the  excessive  amount 
of  butter  off  with  a  string.  The  extra  butter  can  then  be  rolled 
off,  and  the  top  appear  perfectly  smooth  and  full. 


PACKING  AND    MARKETING  BUTTER. 


275 


The  surface  of  the  tubs  should  be  neatly  finished  by  pleating 
the  lining  of  the  tub  over  onto  the  top  of  the  butter.  The 
lining  should  not  be  allowed  to  lap  over  any  more  than  about 
an  inch.  A  cloth  circle  should  then  be  neatly  put  on.  A 


FIG.  162. — Tub-fasteners;  common  tins. 

handful  of  salt  sprinkled  on  the  top  of  this  circle  is  advisable. 
A  little  water  may  be  sprinkled  on  to  cause  the  salt  to  become 
wet.  Some  butter-makers  prefer  an  additional  paper  circle 
on  top  of  the  salt  again. 


FIG.  163. — Tub-fasteners;  tin  and  tack  combined. 

Packing  Butter  for  Exhibition  Purposes. — In  case  butter  is 
to  be  opened  and  scored  several  times,  it  is  advisable  to  use  paper 
circles  instead  of  cloth  circles.  Cloth  circles  give  a  much  better 
appearance  when  the  tubs  are  not  to  be  opened  often,  but  they 


FIG.  164. — Tub-f asteners ;  riveted. 

are  difficult  to  readjust  after  they  have  been  taken  out  of  posi 
tion,  while  the  paper  circle  can  be  taken  off  and  replaced  as 
often  as  desired.  This  applies  especially  to  butter  entered 
for  scoring  contests,  where  the  keeping  quality  of  butter  has 
to  be  tested  also.  Twenty-pound  ash  tubs  are  generally  Used 
for  exhibition  purposes.  Ash  tubs  take  a  little  better  finish 


276 


BUTTER-MAKING. 


than  do  spruce  tubs.  Sandpapering  the  tubs  on  the  outside 
gives  a  nice  appearance.  A  fine  appearing  tub  may  count  con- 
siderably when  the  final  decision  is  rendered.  In  order  to  keep 
the  tub  in  a  clean  and  good  condition  during  transit  special 
precautions  should  be  taken  by  the  sender.  A  good  way  of 
preparing  a  tub  is  to  tack  the  address  on  the  cover,  wrap  the 
tub  well  in  paper,  and  fasten  the  paper  by  wrapping  a  string 
around  the  tub  a  few  times.  Drive  no  more  nails  in  the  tub 
than  is  necessary.  Three  tins  are  sufficient  to  fasten  the 
cover  to  the  tub.  The  tin  fasteners  should  be  placed  equal 
distances  apart.  After  the  paper  has  been  wrapped  around 


FIG.  165. — The  Lafayette  lever  butter-printer. 

the  tub  the  whole  should  be  burlapped.  These  burlaps  can 
be  obtained  with  the  tubs  from  any  of  the  creamery  supply- 
houses.  The  tub  should  then  be  labeled,  and  it  is  ready  for 
shipment. 

Another  good  way  of  preparing  a  tub  for  shipment  is  to 
pack  the  20-pound  tub  into  a  60-pound  tub.  Fill  the  space 
between  the  small  and  the  large  tub  with  paper.  This  is  con- 
sidered by  many  to  be  the  best  method  of  shipping  butter  for 
contests,  as  the  paper,  packed  in  on  the  sides  of  the  tub,  pre- 
vents the  heat  from  penetrating.  In  cold  weather  it  also  pre- 
vents the  butter  from  freezing,  at  least  in  a  measure. 

Storing  Butter  in  Creameries. — The  temperature  of  the 
room  in  which  the  butter  is  being  stored  should  be  as  low 
as  conditions  will  permit.  A  temperature  of  50°  F.  or  below 
is  favorable  to  the  keeping  quality  of  the  butter.  Usually  the 


PACKING  AND  MARKETING  BUTTER. 


277 


butter  is  kept  at  the  creamery  for  from  half  a  week  to  a  whole 
week.  It  is  advisable  to  ship  as  often  as  is  considered  con- 
sistent with  the  amounts  of  butter  handled.  The  refrigerator 
in  which  the  butter  is  kept  at  the  creamery  should  be  kept 
as  pure  and  dry  as  possible.  Damp  places  are  always  con- 
ducive to  the  growth  of  germs,  especially  moulds.  Vegetables 
or  foods  of  other  kinds  should  not  be  allowed  in  the  refrigerator 


FIG.  166. — The  engine-room  of  Littleton  Creamery  Co.     (Creamery  Journal.) 

with  the  butter,  as  they  are  likely  to  impart  foreign  flavors  to 
the  butter.  Mechanical  refrigeration  and  cooling  with  ice  are 
the  best  cooling  facilities.  In  case  it  should  happen  that  it  is 
impossible  to  obtain  ice,  water  can  be  utilized  for  this  purpose. 
The  water  used  in  the  creamery  can  be  made  to  run  through 
a  galvanized-iron  tank.  This  tank  is  properly  placed  in  the 
butter  storing-room,  or  refrigerator,  so  as  to  allow  as  much 
cooling-surface  in  the  butter-room  as  possible.  This  method 


278 


BUTTER-MAKING. 


will  not  cool  the  room  as  effectively  as  ice,  but  in  the  absence 
of  ice  this  is  better  than  no  cooling  at  all. 

Cost  of  Producing  One  Pound  of  Butter. — The  cost  of  pro- 
ducing a  pound  of  butter  varies  at  different  creameries.  Up 
to  a  certain  limit,  the  more  butter  that  is  being  produced  at 


FIG.  167. — Cross-section  of  a  sewage-disposal  tank.     (Wallace's  Farmer.) 

one  place  the  less  will  be  the  cost  of  production,  that  is,  pro- 
viding the  creameries  are  otherwise  equally  well  managed. 
The  Iowa  State  Dairy  Commissioner  has  investigated  this 


Waste  Water  from  Cream  Vats  and  Starter  Can 


FIG.  168. — Septic  tank  for  creamery  sewage  disposal.  (By  Prof.  J.  Michels.) , 
The  tank  should  be  located  in  the  ground  with  the  top  within  a  foot  or 
two  of  the  surface.  It  may  be  constructed  of  planks.  Brick,  stone,  or 
concrete  is  preferable  for  durability.  The  tank  should  be  built  air- 
tight except  in  two  places,  D  and  E. 

question  and  finds  that  the  cost  of  production  varies  from 
1.2  cents  to  6  cents  per  pound.  According  to  the  reports  sub- 
mitted to  the  office  of  the  State  Dairy  Commissioner,  the 
highest  cost  of  production  comes  from  a  co-operative  creamery 
that  makes  a  little  less  than  30,000  pounds  of  butter  per  year. 
The  lowest  cost  of  production  is  submitted  by  a  co-operative 


PACKING  AND  MARKETING  BUTTER. 


279 


280 


BUTTER-MAKING. 


creamery  making  nearly  half  a  million  pounds  of  butter  from 
whole  milk  exclusively.  The  approximate  average  cost  of  mak- 
ing butter  for  the  whole  State  of  Iowa  in  the  whole-milk  cream- 
eries is  about  2£  cents  per  pound.  As  the  creameries  produce 
on  an  average  about  150,000  pounds  of  butter  per  year,  the 
running  expenses  of  the  average  creamery  are  approximately 
$2350.00  per  year. 

The  following  table  will  show  the  variation  in  cost  of  pro- 
duction per  pound  of  butter: 


Class. 

Creamery  Cost  of  Manufacturing  a  Pound  of  Butter. 

No. 
Reported. 

Cost, 
Cents. 

1 

Creameries  making  no  more  than  50,000  Ibs.  of 
butter  

44 

3  14 

2 

Creameries  making  between  50,000  and  100,000 
Ibs.  of  butter  

98 

2  36 

3 

Creameries  making  between  100,000  and  150,000 
Ibs  of  butter     ...                                   

53 

1  99 

4 

Creameries  making  between  150,000  and  200,000 
Ibs.  of  butter  

28 

1  78 

5 

Creameries  making  between  200,000  and  300,000 
Ibs  of  butter  

27 

1  71 

Average  for  the  State  

253 

2  28 

Average  for  classes  2  and  3  

154 

2  22 

CHAPTER  XIX. 
COMPOSITION  OF  BUTTER. 

BUTTER  is  composed  of  fat,  water,  proteids,  milk-sugar, 
ash,  and  salt.  The  milk-sugar  and  ash  are  present  in  butter 
only  to  a  very  small  extent.  In  the  analysis  of  butter  the 
milk-sugar  is  usually  included  with  the  proteids  (curd),  and 
the  ash  is  reckoned  in  with  the  salt. 

Storch  gives  the  following  average  composition  of  butter: 

From  From 

Fresh  Cream.     Ripened  Cream. 

Fat 83.75  82.97 

Water 13.03  13.78 

Proteids  (curd) 64  .84 

Milk-sugar 35  .39 

Ash 14  .16 

Salt 2.09  1.86 

The  average  composition  of  butter  as  determined  from  the 
analysis  of  221  samples,  representing  55  different  creameries 
in  different  parts  of  the  State  of  Iowa,  is  as  follows : 

Fat 84 

Water 12.73 

Curd 1.30 

Salt  and  ash 1 .97 

EFFECT  OF  COMPOSITION  OF  BUTTER  UPON  QUALITY. 

The  quality  of  cream  or  milk  from  which  the  butter  has  been 
produced  and  the  methods  employed  in  the  manufacture  have 
more  effect  upon  the  quality  of  butter  than  has  the  composi- 

281 


282  BUTTER-MAKING. 

tion.  A  small  variation  in  the.  components  of  butter  affects 
the  quality  very  little,  provided  the  butter  has  been  properly 
made,  and  the  components  properly  incorporated.  In  the 
same  creamery  the  composition  of  butter  varies  according  to 
the  season  of  the  year,  from  day  to  day,  and  even  from  one 
churning  to  another.  According  to  the  present  methods  of 
manufacture,  water,  salt,  and  fat  are  the  components  most 
likely  to  vary.  Casein  varies  very  little. 

Curd  and  Sugar. — Occasionally  the  curd  content  may  go  as 
high  as  4%.  It  rarely  exceeds  2%,  and  seldom  falls  below  .5 
of  1%.  A  high  curd-content  will  show  itself  in  the  butter  in 
the  form  of  a  milky  brine,  or  in  the  form  of  white  specks.  If 
there  is  less  than  2%  of  curd  present  in  the  butter,  the  brine 
shows  no  noticeable  milkiness.  More  than  that  much  curd 
can,  as  a  rule,  be  detected  from  the  color  of  the  brine. 

If  the  casein  or  the  curd  has  been  incorporated  in  the  form 
of  small  lumps  or  specks,  then  abnormal  amounts  of  curd 
appear.  When  the  sample  of  butter  is  taken  for  analysis,  such 
a  speck  of  curd  present  in  the  sample  raises  the  final  curd-con- 
tent to  a  comparatively  high  figure. 

As  has  been  mentioned  before,  the  curd  and  milk-sugar  are 
incorporated  from  the  buttermilk  into  the  butter  during  the 
churning.  In  manufacturing  butter  for  storage,  these  sub- 
stances should  be  excluded  from  the  butter  as  thoroughly  as 
possible.  The  milk-sugar  and  albuminoids  constitute  the  chief 
food  for  bacterial  growth.  As  the  deterioration  of  butter  has 
been  demonstrated  to  be  due  chiefly  to  the  action  of  organisms, 
it  becomes  essential  to  restrain  their  growth  as  much  as  passible 
by  excluding  food  necessary  for  their  growth. 

Salt. — In  the  chapter  discussing  the  salting  of  butter,  it  was 
mentioned  that  a  small  increase  or  decrease  in  the  salt-content 
of  butter  can  be  recognized  by  most  consumers,  while  the  same 
variation  in  the  other  constituents  cannot  be  noticed  so  easily. 
The  average  salt-content  of  butter  is  about  2%.  As  the  amount 
of  salt  properly  dissolved  in  butter  depends  upon  the  amount 
of  water  present,  the  first  important  step  in  controlling  the  salt- 


COMPOSITION  OF  BUTTER. 


283 


content  is  to  have  reasonable  cpntrol  of  the  water- content  of 
the  butter.  If  there  is  no  more  than  16%  of  water  present  in 
the  butter,  it  is  desirable  to  have  as  much  salt  in  as  the  water 
will  dissolve  within  the  time  usually  allotted  for  that  purpose. 
This  much  salt  suits  most  of  the 
American  butter  markets.  The 
authors  have  analyzed  commercial 
butter  containing  more  than  8%  salt. 
The  major  portion  of  this  was  present 
in  an  undissolved  condition.  Such 
butter  is  called  gritty,  and  is  ob- 
jected to  by  most  consumers. 

Salt  acts  as  a  preservative  and 
adds  flavor  to  the  butter,  provided 
it  is  in  good  condition.  It  is  said 
that  the  addition  of  salt  has  some 
effects  upon  the  body  of  the  butter. 
Richmond  asserts  that  salty  butter 
loses  more  water  on  standing  than 
unsalted  butter.  This  is  undoubt- 
edly due  to  the  leaky  condition  which  is  brought  about  when 
salt  is  added  to  butter  while  in  a  granular  condition.  .  Salt 
attracts  moisture.  Unsalted  butter  would  not  be  exposed  to 
this  influence  of  the  salt.  When  kept  unsalted,  butter  usually 
becomes  cheesy  in  flavor  in  a  short  time,  while  salted  butter 
assumes  entirely  different  characteristics. 

Water. — The  moisture-content  of  butter  may  vary  between 
6%  and  16%.  Frequently  butter  is  found  that  contains  more 
than  16%,  but  this  amount  is  in  violation  of  the  law.  Butter 
may  contain  as  much  as  18%  of  water,  if  properly  incorporated, 
without  affecting  its  apparent  commercial  quality.  Water  is 
present  in  a  greater  proportion  than  any  other  non-fat  con- 
stituent. Its  variation  is  also  greater  than  that  of  any  other 
constituent.  The  fat  will,  of  course,  vary  with  the  water. 
The  more  water  there  is  present  in  the  butter,  the  less  fat  there 
will  be,  and  the  less  water,  the  more  fat.  As  butter  is  bought 


FIG.  170. — Ice-crusher. 


284  BUTTER-MAKING. 

with  the  understanding  that  it  is  rich  in  fat,  much  objection  has 
been  raised  to  butter  containing  an  abnormal  amount  of  water. 
This  objection  by  consumers  is,  of  course,  a  just  one.  The 
producers  desire  to  incorporate  as  much  water  as  is  consistent 
with  good  quality.  Butter  containing  a  high  moisture -con- 
tent, more  than  18%,  will  appear  .dead  and  dull.  It  is  sticky, 
and  when  sampled  with  a  trier  it  is  next  to  impossible  to  draw  a 
full  trier  of  butter.  It  shrivels  and  rolls  on  both  sides  of  the  trier 

Moisture  affects  butter  in  two  principal  ways,  according  to 
the  way  in  which  is  is  incorporated:  (1)  By  causing  leaky 
butter,  and  (2)  by  making  the  butter  appear  dull. 

1.  This  leaky  condition  in  commercial  butter  is  very  common. 
It  has  been  a  common  opinion  among  butter- judges  that  when- 
ever water  appears  in  large  drops  on  the  butter,  and  some- 
what slushy  when  sampled,  the  butter  contains  too  much 
moisture.  This,  however,  is  not  always  the  case,  as  butter  will 
not  as  a  rule  hold  an  excessive  amount  of  moisture  in  that  form. 
Even  if  this  leaky  butter  does  not  contain  an  excess  of  moisture, 
it  is  a  very  undesirable  condition,  as  most  consumers  object 
to  this  apparent  slushiness.  As  has  been  stated  before,  this 
leaky  condition  is  brought  about  chiefly  by  churning  the  butter 
to  small  granules,  washing  the  butter  very  little  in  cold  water, 
salting  heavily,  while  butter  granules  are  still  small  and  firm, 
and  working  the  butter  frequently  in  the  presence  of  brine. 
When  moisture  is  properly  incorporated  in  butter,  it  should 
be  present  in  exceedingly  minute  drops.  In  a  fine  state  of 
division  it  will  not  escape  from  the  butter. 

This  leaky  condition  of  moisture  in  butter  may  give  a  wrong 
impression  to  consumers  about  its  moisture-content.  Major 
Alvord,  Chief  of  Dairy  Division  of  U.  S.  Department  of  Agri- 
culture, reports  that  a  great  many  buyers  on  the  English  market 
have  the  opinion  that  American  butter  contains  an  excess  of 
moisture.  This  conclusion  evidently  has  been  reached  on 
account  of  the  water  in  American  butter  often  appearing  in 
this  leaky  condition,  as  described  above.  In  reality  it  is  low 
in  its  moisture-content. 


COMPOSITION  OF  BUTTER.  285 

2.  The  dull  and  dry  appearing  condition  of  butter  may  be 
due  (1)  to  the  presence  of  an  excess  of  moisture  properly  incor- 
porated; (2)  to  the  treatment  the  butter  receives  during  manu- 
facture. When  the  dull  and  dry  appearance  is  due  to  moisture, 
the  water  has  been  incorporated  during  the  churning,  or  during 
the  washing  process,  through  excessive  churning  or  working 


FIG  .  171 . — Rubber  mop. 

in  the  buttermilk  or  wash-water  at  a  high  temperature.  The 
dullness  may  also  be  brought  about  by  overworking  the  butter. 
If  the  butter  has  been  overworked,  as  a  rule,  it  contains  little 
moisture,  though  its  appearance  may  be  like  that  of  butter 
containing  an  excess. 

The  conditions  which  affect  the  moisture-content  of  butter 
during  its  manufacture  are: 

(1)  Temperature  of  cream  and  of  wash- water.    The  higher 
the  temperature  of  these  two  substances,  the  more  water  will 
be  incorporated  in  the  butter.     When  the  temperature  is  too 
high,  the  body  of  the  butter  is  injured  materially.     The  keeping 
quality  of  the  butter  is  also  injured  by  having  the  temperature 
of  the  cream  too  high.     The  buttermilk  constituents  are  incor- 
porated with  the  butter  and  cause  it  to  deteriorate  rapidly. 

(2)  The  amount  of  churning  in  buttermilk  and  wash-water. 
The  more  the  butter  is  being  churned  or  worked  in  the  presence 
of  moisture,  the  more  water  the  butter  will  contain.     When  the 
temperature   of   buttermilk   and  wash-water    is    low,  a  small 
amount  of  churning  affects  the  moisture-content  very  little, 
while  if  the  temperature  is  high,  great  care  should  be  taken 
not  to  overchurn. 

(3)  Per  cent  of  fat  in  cream.    The  thicker  the  cream  the 
more  moisture  there  will  be  present  in  the  butter.     In  order  to 


286  BUTTER-MAKING. 

churn  thick  cream,  a  higher  temperature  is  necessary.  It  is 
difficult  to  stop  the  churn  without  over  churning  a  trifle.  These 
two  conditions,  thick  cream  and  high  temperature,  are  both 
conducive  to  a  higher  moisture- content. 

(4)  Amount  of  work  the  butter  receives.  If  the  butter  is 
in  a  moderately  firm  condition,  the  more  the  butter  is  worked, 
in  the  absence  of  water,  the  less  moisture  it  will  contain.  If 
the  moisture  is  present  in  a  leak}^  form  as  mentioned  above,  it 
is  expelled  to  a  great  extent  by  working.  But  if  the  moisture 
is  properly  incorporated  and  the  butter  is  not  too  firm,  work- 
ing has  little  effect  upon  changing  the  moisture-content  of  the 
butter,  providing  there  is  no  water  present  in  the  churn. 

Several  other  factors,  such  as  pasteurization  of  cream,  full- 
ness of  churn,  and  character  of  fat  in  cream,  all  have  a  small 
influence  in  governing  the  moisture-content  of  butter,  but  in 
this  summary  it  is  sufficient  to  say  that  temperature,  degree 
of  churning,  and  thickness  of  cream  are  the  only  conditions 
which  materially  influence  the  moisture- content.  If  churning 
is  carried  on  to  an  excess,  whether  it  be  in  the  buttermilk  or 
in  the  wash-water,  all  other  factors  are  subordinate  and  have 
little  or  no  influence  in  regulating  the  moisture-content  of 
butter.  Low  temperature  is  the  chief  factor  that  delays  in- 
corporation of  moisture  in  excessive  churning. 

Fat. — The  English,  the  German,  and  the  United  States 
governments  have  endeavored  to  protect  consumers  in  regard 
to  the  amount  of  nutriment  in  butter,  by  recommending  16% 
of  water  as  a  maximum  limit.  Such  a  ruling  has  worked  suc- 
cessfully now  for  several  years.  Efforts  have  recently  been 
made  in  the  United  States  to  base  by  law  the  nutritive  quality 
of  butter  upon  a  certain  minimum  percentage  of  fat.  The 
minimum  amount  of  fat  recommended  by  the  appointed  com- 
mittee of  chemists  is  82^%.  A  minimum  standard  of  82^% 
of  fat  in  butter  would  be  unintentionally  violated,  while  a  basis 
of  80%  fat  in  butter  would  be  more  consistent  with  the  quality 
of  butter  as  manufactured. 


CHAPTER  XX. 

JUDGING  AND  GRADING  BUTTER. 

BUTTER  may  be  judged  from  a  commercial  and  from  an 
individual  standpoint.  Individual  judgments  of  the  same 
butter  may  vary  considerably.  It  is  important  that  the  judge 
should  become  familiar  with  the  quality  of  butter  as  required 
by  our  standard  markets,  and  then  judge  the  butter  according 
to  the  demands  of  the  mass  of  the  consumers,  rather  than 
according  to  personal  likes  and  dislikes.  In  order  to  become 
a  good  butter-judge,  it  is  essential  that  the  senses  of  taste  and 
smell  be  acute.  Even  if  one's  taste  and  smell  are  keen  and  sensi- 
tive, considerable  practice  or  experience  is  necessary.  Almost 
any  one  can  tell  a  good  sample  of  butter  from  a  very  poor  one, 
but  when  it  comes  to  differentiate  between  two  samples  which 
are  nearly  alike  in  quality,  skill  and  experience  are  required. 

The  chief  thing  in  scoring  butter  is  to  become  thoroughly 
familiar  with  the  ideal  flavor  of  butter;  then  by  repeated 
comparisons  of  different  samples  of  butter  to  this  one  ideal 
flavor,  one  will  soon  become  efficient  in  grading  the  butter. 

Standard  for  Judging.  —  In  America  the  distinct  qualities 
which  are  noticed  in  butter  are  designated  according  to  the 
basis  of  points  given  below.  It  will  be  noticed  that  different 
values  are  given  to  the  different  characteristics,  according  to 
their  relative  importance.  The  score-card  given  below  is  used 
commercially,  and  is  based  upon  100  as  perfect: 

SCORE-CARD. 
No 

Perfect.  Score.  Remarks. 

Flavor 45  

Body 25  

Color 15 

Salt 10  

Style 5  .". 


Total 100  

Date Scored  by 

287 


288  BUTTER-MAKING. 

At  a  recent  conference  of  the  Societe  Nationale  de  Laiterie, 
held  at  Brussels,  the  following  scale  of  points  was  suggested  for 
butter  (Creamery  Journal) : 

Odor 5 

f  Color 5 

Work  J  Reflection 10 

'rK 1  Cleanliness 5 

[  Chemical  analysis 10 

(  Firmness 13 

Consistency -j  Spreading  facility 12 

[  Interior  structure 5 

Tastp  /  Purity 5 

•  \  Taste  and  aroma 30 

100 

SCORE-CARD  USED  BY  W.  S.  MOORE  &  Co.,  CHICAGO. 

Stencil Date 

Creamery 

Buttermaker.  . 


Too  high  acid 1-3 

Sour 1-3 

Heated 9 

Weedy 2-10. . . 

Tainted 2 

Barny 2-10.  . . 

Poor  sewerage,  dirty  cans,  etc 5-10. . . 

Wintery 2-10.  . . 

Old  milk 2 

Flat 1-3 

Light 1-3 

Summery 1-10 .  . . 

Needs  more  acid 1-3 

Poor  water  or  ice 

Fishy 4-6 

Cowy 1-2-10. 


Fine,  high,  clean.  . 
Score  (Perfect  45). 


Weak 4.. 

Salvy 4.. 

Greasy 4. . . 

Oily 4... 

Tallowy 4..  . 

Cheesy 4 . .  . 

Loose  body 4-7 . 

Too  much  water 4 . .  . 

Not  enough  water 4 . .  . 

Water  not  well  incorporated 4. . . 

Milky 


Fine,  waxy 

Score  (Perfect  25). 


JUDGING  AND  GRADING  BUTTER.  289 


Wavy 4-6 . 

Streaked 4-6. 

Mottled 4-6. 

Too  high 

Too  light 

Not  good  shade 


Fine,  even,  light  straw  colored. 
Score  (Perfect  15) 


Too  high 6.  .  . 

Too  light 6..  . 

Flat 6... 

Gritty 4-6 . 

Fishy 4-6. 

Poor  grade  of  salt.  .  .  „ 

Irregular.  „ 


Fine,  smooth 

Score  (Perfect  10). 


Tops  not  neat 7 . 

Too  much  salt  on  tops 7- 

Tubs  not  full 7. 

Stroke  tops  off  level;  do  not  bevel 7. 

Fold  paper  liners  under  cloth  circles,  not  on  top 

Not  paper  lined 

Liners  poor  grade 

Too  much  brine 7- 

Loosely  packed 7- 

Tubs  dirty 7. 

Tubs  muddy 9 . 

Tubs  soaked  too  much 7- 

Tubs  mouldy 7 . 

Dark-colored  staves 7 . 

Not  Elgin-style  tubs 7 . 

Tubs  flimsy , 7. 

Broken  hoops  and  covers 7. 

Tares  too  light;   11  Ibs.  wanted 8. 

Tares  too  heavy;   11  Ibs.  wanted 8. 

Hooks  or  poor  tin  fasteners 7 


Fine,  handsome.  . 
Score  (Perfect  5) 


Total  score  (Perfect  100). 


290  BUT  TER-MA  KING. 

MANNER  OF  JUDGING. 

Body. — After  the  trier ful  of  butter  has  been  drawn  out, 
the  first  thing  to  notice  is  the  aroma,  and  the  body  or  texture 
of  the  butter.  The  butter  on  the  outside  should  be  examined 
at  once  before  it  is  affected  by  the  temperature  of  the  room. 
Notice  its  color,  whether  it  is  even  or  uneven,  low  or  high. 
Determine  by  the  appearance  of  the  butter  and  the  way  it  feels 
to  the  palate  whether  it  is  greasy,  tallowy,  spongy,  or  sticky. 
The  amount  of  brine  and  condition  of  brine  should  also  be 
noted.  These  characteristics  and  their  causes  have  been 
previously  discussed.  Stroke  the  plug  of  butter  with  a  knife 
to  observe  the  color  closer.  Squeeze  it  with  the  thumb  to 
ascertain  the  character  of  the  body.  The  aroma  of  the  butter 
should  also  be  noticed  in  connection  with  scoring  the  butter 
on  body  or  texture,  as  it  is  more  pronounced  immediately  after 
the  trierful  of  butter  has  been  drawn. 

Flavor.— It  is  impossible  to  describe  all  the  different  flavors 
found  in  butter.  There  are  perhaps  as  many  distinct  butter 
flavors  as  there  are  shades  of  colors.  However,  there  are  a 
few  flavors  which  stand  out  more  prominent  and  are  more 
commonly  met  with  than  any  of  the  others.  Good  butter 
should  possess  a  clean,  mild,  rich,  creamy  flavor,  and  should 
have  a  delicate,  mild,  pleasant  aroma.  Some  butter  judges, 
especially  foreign  judges,  allow  a  separate  number  of  points 
for  aroma  of  butter  in  the  score-card.  This  has  been  sug- 
gested in  the  United  States  also,  owing  to  the  fact  that 
butter  may  have  little  aroma  and  still  have  a  good  flavor. 
Owing  to  this,  it  has  been  suggested  that  it  would  be  better  to 
allow  a  certain  number  of  points  separately  for  aroma  in  the 
score-card. 

Flat  flavor  is  noticeable  in  butter  made  from  unripened 
cream.  If  such  butter  is  otherwise  clean,  little  objection  is 
made  to  this  kind  of  butter  for  ordinary  commercial  purposes. 
The  remedy  is  to  ripen  the  cream  a  little  higher  with  a  proper 
ferment.  Rancid  flavor  is  applied  to  butter  which  has  an 


JUDGING  AND  GRADING  BUTTER.  291 

undesirable,  strong  flavor.  Rancid  flavor  is  the  most  common 
defect  developing  in  butter  on  standing.  Other  flavors  develop- 
ing in  butter  are  "turpentine/'  "fishy,"  "unclean,"  "feverish," 
and  "stale"  flavors.  In  criticizing  butter  it  is  better  to  mark 
at  once  the  specific  fault,  rather  than  state  that  the  butter 
is  rancid.  Cheesy  flavor  is  another  characteristic  which  is  very 
common  in  butter.  This  cheesy  condition  develops  chiefly 
in  butter  containing  little  or  no  salt.  It  is  claimed  to  be  due 
to  the  decomposition  of  the  proteid  matter  in  the  butter. 
Weedy  flavors  are  quite  common  in  butter.  They  are  due 
mostly  to  the  condition  of  milk  previous  to  the  manufacture 
of  the  butter.  The  remedy  is  to  take  the  cows  away  from  the 
pasture  in  which  weeds  of  different  kinds  are  growing,  such  as 
garlic,  wild  onions,  etc.  Acid  flavor  is  another  common  defect 
found  in  butter.  It  is  usually  due  to  improper  ripening  of 
cream .  The  term  sour  is  used  in  its  literal  meaning  in  describing 
butter  which  in  reality  is  sour,  though  not  very  sour  to  the 
taste;  by  the  sense  of  smell,  however,  the  sourness  is  readily 
perceived.  The  usual  cause  of  this  sourness  is  an  improper 
removal  of  the  buttermilk  before  the  butter  is  packed.  The 
term  sour  is  occasionally  used  to  designate  butter  which  has 
been  made  from  overripened  cream.  Feverish  flavor  is  a 
comparatively  new  term.  Its  significance  seems  to  be  of 
importance.  This  flavor  is  very  sickening.  It  is  believed  to 
be  due  to  the  cow's  system  being  in  an  unhealthy  condition. 
This  flavor  is  imparted  to  the  butter  when  it  is  produced  from 
milk  drawn  from  cows  during  sexual  excitement.  Diarrhoea 
of  the  cows  is  claimed  to  produce  the  same  effect.  Stable 
flavors  are  due  to  the  improper  and  unclean  conditions  of  the 
barn.  They  are  most  common  during  the  winter,  when  cows 
are  exposed  to  stable  conditions. 

Color. — The  color  should  be  bright  and  even.  When  a  plug 
of  butter  is  drawn  with  a  trier  and  is  held  up  to  the  light,  it 
should  not  be  cloudy  and  dense,  but  should  be  almost  transparent 
and  bright.  The  chief  fault  found  with  the  color  of  butter 
is  unevenness.  It  may  be  streaky,  mottled,  or  it  may  be  too 


292  BUTTER-MAKING. 

high  or  too  low.  The  shade  of  color  will  vary  according 
to  the  different  markets.  The  color  preferred  in  our  markets 
is  chiefly  a  high  straw  color.  There  has  been  a  tendency  re- 
cently to  recommend  a  comparatively  high  color  in  butter,  in 
order  to  distinguish  it  from  oleo  margarine.  A  reddish  color, 
however,  should  be  guarded  against,  except  when  the  market 
demands  it.  If  too  much  color  is  added,  butter  will  assume 
this  hue,  which  is  very  undesirable. 

Salt. — The  amount  of  salt  likewise  depends  upon  the  market, 
and  unless  the  salt-content  is  extremely  high,  or  extremely 
low,  butter  should  not  be  criticized  on  account  of  the  amount 
of  salt.  The  chief  thing  to  consider  in  judging  butter  on  its 
salt-content  is  the  condition  of  the  salt.  Notice  whether  it 
has  been  thoroughly  dissolved  and  evenly  distributed. 

Style. — The  style  is  the  appearance  of  the  butter  and  package- 
Whatever  the  shape  of  the  package,  the  chief  thing  to  consider 
is  that  it  is  clean  and  neatly  finished,  as  described  in  the  para- 
graph on  "Exhibition  of  Butter." 


CLASSIFICATION  AND  GRADES  OF  BUTTER. 

The  classification  and  grading  of  butter  on  the  different 
markets  vary  very  little.  As  the  New  York  market  is  the 
great  butter  market  in  the  United  States,  we  quote  the  classi- 
fication and  grades  of  butter  as  outlined  by  the  New  York  Mer- 
cantile Exchange: 

"CLASSIFICATION. 

"  1.  Butter  shall  be  classified  as  Creamery,  Process,  Factory, 
Packing  Stock,  and  Grease  Butter. 

"DEFINITIONS. 

"2.  Creamery. — Butter  offered  under  this  classification 
shall  have  been  made  in  a  creamery  from  cream  separated  at 
the  creamery  or  gathered  from  farmers. 


JUDGING  AND  GRADING  BUTTER.  293 

"3.  Process. — Butter  offered  under  this  classification  shall 
be  such  as  is  made  by  melting  butter,  clarifying  the  fat  there- 
from and  re-churning  the  same  with  fresh  milk,  cream,  or 
skim-milk,  or  other  similar  process. 

"4.  Factory. — Butter  offered  under  this  classification  shall 
be  such  as  is  collected  in  rolls,  lumps,  or  in  whole  packages  and 
reworked  by  the  dealer  or  shipper. 

"5.  Packing  Stock. — Butter  offered  under  this  classification 
shall  be  original  farm  made  butter  in  rolls,  lumps  or  otherwise, 
without  additional  moisture  or  salt. 

"6.  Grease  Butter. — This  shall  comprise  all  classes  of  butter 
grading  below  thirds,  or  of  packing  stock  grading  below  No.  3, 
as  hereinafter  specified,  free  from  adulteration. 

"GRADES. 

"7.  Creamery,  process,  and  factory  shall  be  graded  as 
Specials,  Extras,  Firsts,  Seconds,  and  Thirds;  and  Packing 
Stock  shall  be  graded  as  No.  1,  No.  2,  and  No.  3. 

Definition  of  Grades. 

"8.  Grades  of  butter  must  conform  to  the  following  re- 
quirements in  addition  to  the  requirements  of  score  as  here- 
inafter provided. 

"9.  Specials. — Shall  comprise  the  highest  grades  of  butter 
obtainable  in  the  season  when  offered,  under  the  various  classi- 
fications. 90%  shall  conform  to  the  following  standard;  the 
balance  shall  not  grade  below  Extras. 

"Flavor. — Must  be  fine,  sweet,  clean,  and  fresh,  if  of  cur- 
rent make,  and  fine,  sweet  and  clean,  if  held. 

"Body. — Must  be  firm  and  uniform. 

"Color. — A  light  straw  shade,  even  and  uniform. 

"Salt. — Medium  salted. 

"Package. — Sound,  good,  uniform,  and  clean. 

"Specials  may  also  comprise  such  lots  of  Extras  as,  owing 
to  some  particular  and  unusual  qualification,  are  more  de- 
sirable than  plain  " extras"  offered  without  any  qualification. 


294 


BUTTER-MAKING. 


"10.  Extras. — Shall  be  a  grade  just  below  Specials  and  must 
be  fine  butter  for  the  season  when  made  and  offered,  under 


Graphical  illustration  of  the  approximate  relative  amount  of  each  of  the 
different  grades  of  butter  arriving  on  the  New  York  market  during  the 
summer  season.  It  also  shows  the  required  score  for  each  of  the  dif- 
ferent grades.  (From  N.  Y.  Produce  Review.) 

the  various  classifications.  90%  shall  conform  to  the  follow- 
ing standard;  the  balance  shall  not  grade  below  Firsts. 

"Flavor.— Must  be  sweet,  clean,  and  fresh  if  of  current 
make  and  sweet  and  clean,  if  held. 

"Body. — Must  be  good  and  uniform. 


JUDGING  AND  GRADING  BUTTER.  295 

"Color. — A  light  straxv  shade,  even  and  uniform. 

"Salt. — Medium  salted. 

"Package. — Sound,  good,  uniform,  and  clean. 

"11.  Firsts. — Shall  be  a  grade  just  below  Extras  and  must 
be  good  butter  for  the  season  when  made  and  offered,  under 
the  various  classifications.  90%  shall  conform  to  the  follow- 
ing standard;  the  balance  shall  not  grade  below  Seconds. 

"Flavor. — Must  be  good,  sweet,  and  fresh  if  of  current  make 
and  good  and  sweet,  if  held. 

"Color. — Reasonably  uniform,  neither  very  high  nor  very 
light. 

"Salt. — May  be  reasonably  high,  light  or  medium. 

"Package. — Good  and  uniform. 

"12.  Seconds. — Shall  be  a  grade  just  below  Firsts. 

"Flavor. — Must  be  reasonably  good. 

"Body. — If  Creamery,  must  be  solid  boring.  If  Factory  or 
Process,  must  be  90%  solid  boring. 

"Color. — Fairly  uniform,  but  may  be  mottled. 

"Salt. — May  be  high,  medium,  or  light. 

"Package. — Good. 

"13.  Thirds. — Shall  be  a  grade  below  Seconds  and  may 
consist  of  promiscuous  "ots. 

"Flavor. — May  be  off-flavored  and  strong  on  tops  and 
sides. 

"Body. — Not  required  to  draw  a  full  trier. 

"Color. — May  be  irregular  or  mottled. 

"Salt. — High,  light,  or  irregular. 

"Package. — Any  kind  of  package  mentioned  at  time  of 
sale. 

"14.  No.  i  Packing  Stock. — Shall  be  sweet  and  sound, 
packed  in  large,  new,  or  good  uniform  second  hand  barrels, 
having  a  wooden  head  in  each  end,  or  in  new  tubs,  either  to 
be  parchment  paper  lined.  Barrels  and  tubs  to  be  packed  full. 

"15.  No.  2  Packing  Stock. — Shall  be  reasonably  sweet  and 
sound,  and  may  be  packed  in  promiscuous  or  different  kinds  of 
barrels,  tubs,  or  tierces,  without  being  parchment  paper  lined, 


296  BUTTER-MAKING. 

and  may  be  packed  in  either  two-headed  or   cloth-covered 
barrels. 

"16.  No.  3  Packing  Stock.— Shall  be  a  grade  below  No.  2, 
and  may  be  off-flavored,  or  strong;  may  be  packed  in  any 
kind  or  kinds  of  packages.  Charges  for  inspection  shall  be 
the  same  as  the  rules  call  for  on  other  grades. 

"Scoring,  as  Affecting  Grades  of  Creamery  Butter. 

"17.  In  the  inspection  of  creamery  butter  for  grade,  the 
point  system  of  scoring  shall  be  used  on  the  following  basis: 

"Flavor,  for  perfection 45  points. 

"Body,  for  perfection 25  points. 

"Color,  for  perfection 15  points. 

"Salt,  for  perfection 10  points. 

"Style,  for  perfection 5  points. 

"Total,  for  perfection 100  points. 

"18.  The  Butter  Committee  shall  determine  and  prescribe 
from  time  to  time  a  range  of  scores  covering  two  consecutive 
full  points,  which  shall  be  required  for  the  grade  of  Extra 
Creamery  in  addition  to  the  other  specific  requirements  men- 
tioned in  Rule  10.  The  required  scores  for  Extra  Creamery 
shall  be  fixed  with  due  consideration  for  the  varying  average 
quality  of  the  creamery  butter  obtainable  from  season  to 
season,  and  with  a  view  of  making  this  grade  represent  as 
nearly  as  may  be  a  uniform  quality  relatively  to  the  quality 
of  the  supply  as  a  whole.  The  required  range  of  scores  so  deter- 
mined upon  shall  remain  in  force  until  changed  by  the  Butter 
Committee;  such  changes  may  be  made  at  any  time  and  shall 
become  effective  on  the  day  following  authoritative  announce- 
ment from  the  caller's  desk  and  posting  on  the  bulletins.  All 
creamery  butter  scoring  higher  than  required  for  Extras,  if 
it  meet  the  requirements  mentioned  in  Rule  9,  shall  grade  as 
Creamery  Specials;  all  creamery  butter  scoring  lower  than 
required  for  Extras,  but  not  more  than  four  points  lower, 
if  it  meet  the  requirements  mentioned  in  Rule  11,  shall  grade 


JUDGING  AND   GRADING  BUTTER.  297 

as  Creamery  Firsts;  all  creamery  butter  scoring  lower  than 
Creamery  Firsts,  but  not  more  than  five  points  lower,  if  it 
meet  the  requirements  mentioned  in  Rule  12,  shall  grade  as 
Creamery  Seconds;  all  creamery  butter  scoring  lower  than 
Creamery  Seconds  if  it  meets  the  requirements  of  Rule  13, 
shall  grade  as  Creamery  Thirds. 

"19.  The  Butter  Committee  shall  cause  to  be  posted  in 
a  conspicuous  place  upon  the  bulletins  of  the  Exchange,  the 
range  of  scores  required  for  the  various  grades  of  creamery 
butter  currently  in  effect. 

"20.  Lines  of  fifty  tubs  or  more  of  one  straight  mark  and 
invoice  of  Extra  Creamery  butter  shall  be  a  good  delivery  on  a 
contract  for  Creamery  Specials,  provided  the  guaranteed  score 
of  the  butter  is  mentioned  when  the  goods  are  offered  for 
sale. 

" Known  Marks. 

"21.  Known  marks  shall  comprise  such  butter  as  is  known 
to  the  trade  under  some  particular  mark  or  designation  and 
must  grade  as  Extras  or  better  if  Creamery  or  Process,  and  as 
Firsts  or  better  if  Factory  in  the  season  when  offered,  unless 
otherwise  specified.  Known  marks  to  be  offered  under  the 
call  must  previously  have  been  registered  in  a  book  kept  by 
the  Superintendent  for  that  purpose.  If  Process,  the  factory 
district  number  and  state  must  be  registered. 

"Sales  Under  the  Call. 

"22.  Parties  wishing  to  offer  butter  not  described  in  the 
foregoing  classifications  and  grades,  must  specify  its  character. 

"23.  All  butter  offered  under  the  Call  shall  be  fresh  made, 
current  receipts,  and  shall  be  in  regular  60-pound  ash  tubs, 
unless  otherwise  specified. 

"24.  No  offer  to  buy  or  sell  less  than  twenty-five  tubs  spot, 
nor  less  than  fifty  tubs  for  future  delivery,  nor  bids  or  offers 
of  a  less  fraction  than  Jc.  per  pound  shall  be  entertained. 

"25.  Bids  and  offerings  of  not  less  than  fifty  tubs  for  future 


298  B UTTER-MA  KING. 

delivery  may  be  made  for  a  period  of  ten  days.  The  call  for 
futures  shall  take  place  immediately  after  the  call  for  spot 
delivery,  and  seller  this  afternoon.  On  all  sales  for  future 
delivery,  a  compulsory  margin  shall  be  deposited  by  each  party 
to  the  contract  as  specified  in  Rule  2  of  the  Executive  Com- 
mittee. 

"26.  The  first  offer  to  buy  or  sell  at  a  price  shall  be  ac- 
cepted before  subsequent  offers  at  the  same  figure  are  con- 
sidered. 

"27.  Offers  may  be  withdrawn  at  any  time  before  accept- 
ance. 

"28.  Offers  to  sell  at  a  lower,  or  buy  at  a  higher,  price  shall 
vacate  all  previous  bids  and  offerings. 

"29.  A  transaction  shall  vacate  all  previous  bids  and 
offerings. 

"30.  All  differences  as  to  offers,  acceptances,  withdrawals, 
or  irregular  bids,  shall  be  decided  on  the  spot  by  the  officer 
conducting  the  call,  subject  to  an  appeal  to  the  members  present. 
If  an  appeal  is  made,  it  shall  be  put  promptly,  and  a  majority 
of  the  members  present  and  voting  shall  settle  the  difference 
finally. 

"31.  The  Superintendent  shall  have  recorded  daily,  in  a 
book  kept  for  the  purpose,  all  sales  under  the  call,  and  such 
other  sales  on  the  floor  as  may  be  requested  by  the  parties 
thereto,  and  shall  furnish  certificates  of  sales  to  both  seller  and 
buyer. 

"32.  Spot  sales  shall  be  for  spot  cash,  and  butter  sold  for 
future  delivery  shall  be  paid  for  when  delivered,  unless  other- 
wise agreed. 

"33.  All  deliveries  shall  be  from  the  store  of  the  seller, 
providing  it  be  in  Manhattan  Borough  below  Canal  Street, 
otherwise  the  goods  must  be  placed  within  said  limits. 

"34.  All  disputes  must  be  settled  while  the  goods  are  in 
the  seller's  possession. 

"35.  When  spot  sales  are  made,  butter  must  be  ready 
for  immediate  delivery. 


JUDGING  AND  GRADING  BUTTER.  299 

"36.  All  goods  tendered,  inspector's  certificate  attached, 
shall  be  accompanied  by  such  certificate,  and  be  accepted  by 
the  buyer  unconditionally,  provided  all  tubs  are  branded 
according  to  Rule  64. 

"37.  If  butter  tendered  has  not  been  inspected  and  does 
not  appear  to  the  buyer  to  be  of  the  class  and  grade  sold,  the 
seller  shall  be  notified  not  later  than  1  P.M.  He  may  then 
have  it  inspected,  and  if  it  proves  not  to  fulfill  the  require- 
ments of  the  sale,  he  may  make  a  second  delivery  not  later 
than  3  P.M. 

"38.  If  a  second  tender  is  made  and  appears  not  of  the 
class  and  grade  sold,  the  buyer  must  establish  the  quality  by 
an  official  inspection,  for  which  he  shall  make  application  to 
the  Superintendent  not  later  than  4  P.M.  of  the  day  of  the 
sale. 

"When  an  inspection  is  made  and  shows  the  butter  to  be 
of  the  class  and  grade  sold,  the  buyer  shall  accept  the  same, 
and  pay  for  the  inspection. 

"39.  In  sales  for  'future  delivery'  the  delivery  require- 
ments as  to  time,  inspection,  etc.,  shall  be  the  same  as  on  the 
spot  sales  on  the  date  of  delivery,  but  the  rules  governing 
classification  for  grades  in  force  at  time  of  such  sale  shall 
govern  the  quality  of  such  deliveries. 

"40.  In  sales  'seller's  option'  the  seller  shall  notify  the 
buyer  of  his  intention  to  make  delivery  not  later  than  9  A.M. 
on  the  day  of  delivery.  If  'buyer's  option,'  the  buyer  shall 
notify  the  seller  of  his  intention  to  call  for  delivery  at  least 
twenty-four  hours  before  10  A.M.  of  the  day  delivery  is  de- 
manded. 

"41.  On  sales  of  Creamery  of  twenty-five  tubs,  delivery 
may  be  of  not  more  than  two  marks;  on  twenty-six  to  fifty 
tubs,  three  marks;  on' fifty-one  to  one  hundred  tubs,  marks 
containing  not  less  than  twenty-five  tubs  each;  on  larger  lots, 
marks  containing  not  less  than  fifty  tubs  each. 

"42.  On  sales  of  Factory,  or  Process  butter,  delivery  must 
be  of  one  mark,  unless  otherwise  specified. 


300  BUTTER-MAKING. 

"43.  A  carload  shall  consist  of  300  tubs  of  one  mark,  unless 
otherwise  specified. 

"44.  In  case  of  failure  to  deliver  a  carload,  settlement  shall 
be  made  on  the  basis  of  300  tubs. 

"45.  An  application  to  the  Superintendent  for  an  inspection 
of  goods  in  controversy,  if  made  within  the  time  allowed  for 
inspection,  shall  be  deemed  a  compliance  with  these  rules  in 
this  respect. 

"Penalties. 

"46.  When  an  inspection  of  butter  sold  for  spot  delivery 
shows  the  goods  not  to  be  of  the  class  and  grade  sold,  the  seller 
shall  pay  a  penalty  equal  to  5%  of  the  amount  of  the  contract, 
and  the  fee  for  inspection.  If  the  official  quotation  for  the 
day  exceeds  the  contract  price,  the  seller  shall  also  pay  to  the 
buyer  in  the  same  way  the  difference  between  the  contract 
price,  and  the  average  official  quotation. 

"47.  If  butter  purchased  for  future  delivery  be  not  de- 
livered as  per  contract,  the  buyer  shall  promptly  notify  the 
Superintendent  in  writing.  At  the  next  regular  meeting  of 
the  Exchange,  an  announcement  of  the  same  shall  be  made 
by  the  Superintendent,  who  shall  buy  in  the  goods  for  account 
of  the  seller,  provided  it  can  be  done  under  the  call  at  current 
rates.  If,  however,  the  price  demanded  seems  to  him  un- 
reasonable, he  shall  not  make  the  purchase,  but  shall  refer 
the  matter  to  the  Butter  Committee,  who  shall  determine  the 
difference  between  the  contract  price  and  the  actual  market 
value  on  the  date  on  which  delivery  should  have  been  made, 
and  this  amount,  together  with  a  penalty  equal  to  5%  of  the 
amount  of  the  contract,  shall  be  paid  by  the  seller. 

"48.  If  butter,  sold  for  future  delivery,  be  not  received 
when  properly  tendered,  the  seller  shall  promptly  notify  the 
Superintendent  in  writing.  At  the  next  regular  meeting  of 
the  Exchange,  an  announcement  of  the  same  shall  be  made 
by  the  Superintendent,  who  shall  sell  out  the  goods,  under 
the  call,  for  account  of  the  buyer,  and  if  the  price  obtained  be 


JUDGING  AND  GRADING  BUTTER.  301 

less  than  the  contract  price,  the  difference,  together  with  a 
penalty  equal  to  5%  of  the  amount  of  the  contract,  shall  be 
paid  by  the  buyer. 

"49.  Penalties  and  differences  shall  be  paid  to  the  Super- 
intendent of  the  Exchange,  and  by  him  paid  to  those  entitled 
thereto. 

"50.  Any  member  holding  a  contract  against  another, 
corresponding  in  respect  to  class,  grade,  and  quantity  of  goods, 
and  date  of  delivery,  with  one  held  by  the  other  against  him, 
may  offset  it  against  the  latter  by  giving  notice  to  the  other 
party,  when  both  contracts  shall  be  surrendered  to  the  Super- 
intendent of  the  Exchange  and  cancelled. 

"51.  All  notices  shall  be  in  writing,  and  shall  be  considered 
as  properly  served  when  left  at  the  place  of  business  of  the 
party  for  whom  they  are  intended. 

"Certificate  of  Sale. 

"52.  Certificates  of  sale  must  be  accepted  on  contracts  for 
future  delivery. 

"53.  The  party  transferring  a  certificate  of  sale,  shall  imme- 
diately notify  the  original  seller  of  the  transfer,  and  to  whom 
made.  He  shall  also  have  it  recorded  on  the  books  of  the 
Exchange,  and  shall  thereupon  be  relieved  of  all  responsibility 
attaching  to  the  same. 

"54.  In  case  the  party  to  a  contract  for  future  delivery,  for 
the  fulfillment  of  which  margin  has  been  deposited  with  the 
Superintendent,  shall  die,  make  an  assignment,  be  absent  from 
the  city, or  otherwise  be  disabled,  or  refuse  to  perform  any  act 
necessary  for  the  proper  adjustment  or  payment  of  such  margin, 
the  matter  shall  be  referred  to  the  Finance  Committee,  as 
provided  in  Section  33,  Paragraph  6,  of  the  By-Laws. 

"Contracts. 

"55.  The  following  shall  be  the  form  of  contract  for  all 
sales  of  butter  for  future  delivery: 


302  BUTTER-MAKING. 

"Contract  for  Future  Delivery. 

"No 

"This  is  to  certify  that  the  following  sale  and  purchase 
has  been  made  by  the  respective  signers  hereto,  under  and 
subject  to  the  Rules  of  the  New  York  Mercantile  Exchange, 

this 

day  of 190  

Seller 

Address 

Purchaser 

Address 

Quantity 

Grade  

Score  

Class  

Price 

Delivery 

Seller. 

Purchaser. 

"Original  margins  deposited  with  me  this  day  by  each 

party  hereto dollars. 

" .Superintendent. 

"New  York,   190   

"Upon  the  reverse  side  of  each  contract,  shall  be  printed 
the  Rules  governing  such  transactions.  A  proper  book  shall 
be  kept  by  the  Superintendent  of  the  Exchange,  entitled 
'Butter  Contracts,'  in  which  shall  be  recorded  all  contracts  as 
per  foregoing  form,  duplicates  of  which  shall  be  furnished  to 
both  sellers  and  purchasers,  who  shall  personally  sign  the 
same  at  the  time  of  depositing  original  margins.  All  contracts 
shall  be  signed,  and  original  margins  deposited  not  later  than 
2  o'clock  on  the  day  following  the  sale. 

"56.  When  further  margins  are  called  for,  same  shall  be 
paid  to,  and  receipted  for,  by  endorsement  upon  the  contract 
by  the  Superintendent  of  the  Exchange. 

"57.  All  transfers  of  contracts  for  future  delivery  must  be 


JUDGING  AND  GRADING  BUTTER.  303 

endorsed  on  the  original  contract,  by  the  Superintendent  of 

the  Exchange,  who  shall  promptly  notify  the  other  party  in 

interest,  of  such  transfer. 

"58.  The  following  form  of  transfer  shall  be  used: 

"'For   value    received,    the   within   described    contract   is 

assigned  and  transferred  to 

who  hereby  agrees  to  assume  the  same,  with  all  the  conditions 

and  obligations  thereof. 

"'Dated,  New  York ,    190  

'" Seller. 

"' Buyer.' 

"Inspectors  and  Inspections. 

"59.  At  the  first  meeting  of  the  Butter  Committee  it  shall 
recommend  to  the  President,  for  his  appointment,  subject  to 
the  approval  of  the  Executive  Committee,  such  Inspectors 
of  Butter  as  may  be  required. 

"60.  Vacancies  occurring  in  the  office  of  Inspectors,  shall 
be  filled  in  the  manner  in  .which  the  original  appointment  was 
made. 

"61.  In  case  of  absence  or  inability  of  the  Inspectors, 
temporary  Inspectors  may  be  appointed  by  the  Butter  Com- 
mittee of  the  Exchange. 

"62.  Inspectors,  before  entering  upon  their  duties,  shall  be 
sworn  to  perform  said  duties  faithfully,  and  to  be  governed 
by  the  rules  herewith,  as  they  shall  be  interpreted  by  the 
Butter  Committee,  and  to  make  such  inspections  as  may  be 
directed  by  the  Superintendent  of  the  Exchange. 

"63.  All  applications  for  inspection  must  be  made  to  the 
Superintendent  of  the  Exchange  between  the  hours  of  8.30 
A.M.  and  5  P.M.,  who  will  direct  the  same — for  members  of 
the  Exchange  only — as  soon  as  practicable,  in  the  order 
in  which  they  are  received,  excepting  that  applications  for 
the  inspection  of  butter  which  has  been  sold  under  the  Call, 
and  is  in  controversy,  shall  be  given  precedence  over  other 
applications. 


304  BUTTER-MAKING. 

"64.  Inspectors  shall  brand  on  the  top  and  side  each  pack- 
age inspected,  and  when  requested  also  on  the  side  of  each 
remaining  package  in  the  lot  or  lots  covered  by  the  inspec- 
tion. 

"65.  Inspectors  shall  immediately  after  completing  an  in- 
spection, make  a  certificate  of  the  same  in  accordance  with  the 
specification  for  grading  contained  in  these  rules,  upon  blanks 
furnished  for  this  purpose,  under  the  direction  of  the  Butter 
Committee,  which  shall  be  countersigned  by  the  Superin- 
tendent, and  promptly  delivered  to  the  party  ordering  the 
inspection. 

"66.  A  Certificate  of  Inspection  shall  be  good  for  two  days 
from  date  of  same  (including  Sundays  and  holidays)  provided 
the  holder  of  the  goods  takes  proper  care  of  the  same. 

"67.  The  Inspectors  shall  have  recorded  in  a  book  provided 
for  the  purpose,  a  detailed  account  of  all  inspections  made 
by  them,  stating  date  and  hour  of  inspection,  name,  and  address 
of  parties  for  whom  inspection  is  made,  place  where  inspection 
is  made,  stencil  number  or  other  marks  on  goods,  number  of 
tubs  in  lots,  and  number  of  tubs  inspected.  If  lots  contain 
more  than  one  shipment,  the  number  of  tubs  in  each  shipment 
shall  be  noted. 

"68.  There  shall  be  drawn  as  samples  for  inspection  by  the 
Inspectors : 

5  tubs  from  lots  less  than  25  of  one  mark  and  invoice. 
8    "       •"      "of    25  of  one  mark  and  invoice. 

1  K       I  C  {  C  (  t       (  (         rr\    I  I        (  (  (  (  (l  ll 

20       "  "  "        "1  00    "         "  "  "  •  " 

OK       II  t(  It        tt     900    "        l(  <f  f{  et 

50   "       "      "    "  300 "    "      "      "         " 
60   "        "      "    "  500  "     "       "       "         " 

and  a  like  proportion  of  lots  ranging  between  these  figures, 

and  of  larger  lots. 

"69.  If  butter  runs  irregular  in  quality,  the  Inspector  shall 

increase  his  sample  to  such  an  extent  as  he  deems  necessary 

to  secure  a  fair  and  just  inspection. 


JUDGING   AND  GRADING   BUTTER.  305 

"70.  A  buyer  or  seller  may  have  a  larger  percentage  than 
the  above  inspected,  upon  making  application  previous  to  the 
inspection,  and  payment  of  lOc.  per  tub  additional  fees. 

"71.  All  complaints  against  the  Butter  Inspectors  shall  be 
referred  to  the  Butter  Committee. 

"72.  Charges  for  inspection  shall  be  as  follows: 

On  lots  not  exceeding  10  tubs,  1  invoice SO .  50 

Over    10  and  not  over    25  tubs,  1  invoice 0 . 75 

'•'      "      "      50    "      1       "     1.00 

;'      "      "    100    "      1       "     1.50 

''      "      "    200    "      1       "     1.75 

:<      "      "    300    "      1       "     2.00 

;'      "      "    500    "      1       "     2.50 

"73.  Inspections  shall  be  paid  by  the  party  ordering  the 
same,  excepting  where  otherwise  provided. 

"74.  At  the  first  meeting  of  the  Butter  Committee,  it 
shall  recommend  to  the  President  for  appointment,  subject 
to  the  approval  of  the  Executive  Committee,  a  Butter  Weigher, 
who  may  appoint  assistants  as  he  may  require  them. 

"75.  The  Butter  Weigher  shall  receive  his  instructions 
from  the  Butter  Committee. 

"76.  The  Butter  Weigher  and  Assistants  before  entering 
upon  their  duties  shall  be  sworn  to  perform  said  duties  faith- 
fully, correctly,  and  in  conformity  with  the  customs  of  the 
Butter  Trade,  as  defined  by  the  Butter  Committee. 

"77.  The  Butter  Weigher  shall  make  certificates  in  dupli- 
cate of  all  lots  of  butter  weighed  by  him,  or  his  assistants, 
and  promptly  deliver  to  the  party  ordering  the  weighing. 

"78.  Applications  for  weighing  butter  shall  be  made  to 
the  Superintendent  or  Butter  Weigher. 

"79.  Charges  for  weighing  shall  be  as  follows: 

On  lots  not  over  25  tubs 3c.  per  tub 

Over  25  and  not  over    50  tubs 2£c.  per  tub 

"    50   "      "      "     100    "     2c.     "     " 

Testing  7  tubs  or  less 75c. 

Over  7  tubs.  .  .10c.     "     " 


306  BUTTER-MAKING. 

"80.  All  complaints  against  the  Butter  Weigher,  or  Assist- 
ants, shall  be  made  to  the  Butter  Committee. 

"81.  All  former  rules  conflicting  with  the  foregoing,  are 
hereby  repealed. 

"Attention  is  Directed  to  the  Following  Executive  Committee  Rules, 
and  Section  33,  Paragraph  6,  of  the  By-Laws. 

"Rule  2. — On  all  sales,  or  purchases  of  any  merchandise 
to  arrive,  or  for  future  delivery,  each  party  to  the  contract 
shall  deposit  an  original  margin  with  the  Superintendent  of 
the  Exchange  of  10%  on  the  contract  price  at  the  time  of 
purchase,  or  sale,  and  a  further  margin  from  time  to  time 
to  the  extent  of  any  variation  in  the  market  value  from  the 
contract  price;  said  margin  to  be  deposited  in  such  bank  or 
trust  company  as  may  have  been  designated  by  the  Finance 
Committee  of  the  New  York  Mercantile  Exchange.  When 
margins  are  called  before  12  M.,  they  must  be  deposited  before 
3  P.M.  of  the  same  day.  If  called  after  12  M.,  they  must  be 
deposited  before  12  M.  of  the  following  day;  in  case  of  failure 
to  deposit  as  above,  the  buyer  or  seller  shall  have  the  right 
to  cover  his  contract  at  discretion,  for  account  of  the  party 
failing  to  respond  to  the  call  for  margin. 

"Rule  7. — All  merchandise  purchased  by  sample  shall  be 
considered  sold  unless  the  purchaser  notify  the  seller  within 
twenty-four  hours  after  receipt  of  the  same,  that  it  is  rejected 
as  not  being  up  to  sample.  If  a  settlement  cannot  be  agreed 
on,  the  case  shall  be  referred  to  the  Trade  Committee  having 
charge  of  the  class  of  goods  in  question,  who  shall  decide  the 
matter,  and  in  the  event  of  a  decision  against  either  buyer 
or  seller,  the  same  penalties  shall  accrue  as  the  Rules  under 
the  Call  provide  for  the  kind  of  goods  dealt  in.  The  party 
against  whom  the  decision  is  given  shall  pay  to  each  com- 
mitteeman  serving  $2  for  each  case. 


JUDGING  AND   GRADING   BUTTER.  307 

Section  33,  Paragraph  6,  of  the  By-Laws. 

"When  the  parties  to  a  contract,  on  which  margin  has  been 
deposited  through  the  instrumentality  of  the  Superintendent, 
as  above  set  forth,  cannot  agree  as  to  the  distribution  and 
payment  of  such  margin,  or  in  case  one  or  both  of  the  con- 
tracting parties  die  or  make  an  assignment,  or  otherwise  be- 
come incapacitated,  or  refuse  to  perform  promptly  any  act 
necessary  for  the  adjustment  and  payment  of  such  margin, 
the  Finance  Committee  is  hereby  authorized  and  directed  to 
ascertain  the  person  or  persons  to  whom  such  margins  should  be 
paid,  and  instruct  the  Superintendent  to  endorse  the  deposit 
certificate  for  payment,  or  exchange  it  for  other  checks,  to 
correspond  in  amount  with  the  Committee's  decision,  drawn 
to  the  order  of  the  person  or  persons  entitled  thereto,  and 
deliver  the  same  to  said  person  or  persons  without  unnecessary 
delay;  and  in  case,  for  any  cause  whatever,  the  said  deposit 
certificate  is  not  immediately  forthcoming,  so  that  such  en- 
dorsement and  distribution  may  be  made,  the  Finance  Committee 
shall  instruct  the  Superintendent  to  procure  from  the  said 
bank  or  trust  company  that  issued  it,  a  duplicate  thereof, 
as  provided  for  in  the  original,  and  endorse  it  as  he  would 
have  endorsed  the  original  if  it  had  come  into  his  possession." 

EXPORT  BUTTER. 

The  observations  of  the  authors  have  been  that  the  reputa 
tion  of  the  American  butter  is  not  all  that  is  desirable  on  the 
English  market.  Some  American  butter  is  good  enough  to 
sell  on  an  equality  with  Danish  butter,  and  in  some  instances 
it  is  palmed  off  for  such.  Much  poor  butter,  however,  has  been 
allowed  to  go  onto  the  English  market,  and  this  has  in  some 
measure  ruined  the  reputation  of  our  butter. 

Butter  for  export  purposes  should  be  of  the  very  best,  and 
made  in  such  a  way  as  to  insure  good  keeping  qualities. 

The  standing  of  the  different  kinds  of  butter,  as  observed 
on  the  English  market,  were  as  follows: 


308 


BUTTER-MAKING. 


(1)  Fresh  French  Rolls. 

(2)  Danish  Creamery. 

(3)  Irish  Creamery. 

(4)  New  Zealand. 

(5)  Canadian,   Australian,   Argentine,   United   States,   and 
Siberia. 


For  Storage  Purposes. 


(1)  Danish. 

(2)  New  Zealand. 

(3)  Siberia. 


FIG.  172. — Shipping  Russian  butter  from  Siberia.     (U.  S.  Govt.  Bui.) 


CHAPTER  XXI. 

COOLING   FACILITIES   FOR  CREAMERIES. 

ONE  of  the  most  important  things  in  connection  with  the 
successful  operation  of  a  creamery  is  the  control  of  tempera- 
ture. This  control  of  temperature  is  important  in  the  sepa- 
ration, pasteurization,  ripening,  churning  processes,  and  in 
the  use  and  preparation  of  starters.  Conditions  are  frequently 
such  that  the  raw  as  well  as  finished  dairy  products  need  to 
be  stored.  If  temperature  or  cold  storage  conditions  are  not 
under  control,  dairy  products  will  suffer  in  quality.  Raw  as 
well  as  finished  products  are  very  perishable.  They  are  best 
when  fresh.  Strictly  and  generally  speaking,  dairy  products 
deteriorate  with  age.  The  nearer  the  producers  of  the  raw 
material,  manufacturers,  and  consumers  of  the  finished  prod- 
ucts can  be  brought  together,  the  better  it  is.  Conditions 
of  commerce  and  trade  are  such  that  butter  needs  to  be  pre- 
served for  some  time  before  it  reaches  the  consumer. 

The  preservation  of  butter  depends  on  the  checking  of 
fermentations  affecting  the  flavor  of  this  product.  This  can 
best  be  done  by  the  use  of  a  low  temperature.  There  are 
various  ways  by  which  low  temperature  may  be  obtained  in 
creameries.  The  system  of  refrigeration  to  be  employed  in  a 
given  creamery  should  be  determined  by  local  conditions. 

Cooling  Systems: 

1.  By  the  use  of  natural  ice. 

2.  By  the  use  of  mechanical  refrigeration. 

3.  By  the  use  of  cold  water  alone. 

1.  Most  local  creameries,  within  the  ice-freezing  belt,  make 
use  of  natural  ice.  It  is  by  far  the  most  common  method 

309 


310  BUTTER-MAKING. 

of  refrigeration  employed  in  creameries,  and  undoubtedly,  under 
average  local  conditions,  represents  the  most  economic  method 
of  obtaining  low  temperature.  As  a  rule  patrons  have  little 
work  to  do  during  the  winter  and  are  willing  to  supply  teams 
and  help  for  a  few  days  while  the  ice  is  being  put  up.  The 
use  of  natural  ice  gives  good  satisfaction,  especially  when 
good,  pure  ice  can  be  had  within  a  reasonable  distance  from 
the  creamery,  and  a  proper  and  convenient  place  is  provided 
in  which  to  store  the  ice. 

2.  Mechanical  refrigeration  is  undoubtedly  gaining  favor 
with  creamery-men,  as  is  evidenced  by  the  increased  number 
of  mechanical  refrigerating-plants  installed  in  various  cream- 
eries. The  reasons  for  this  increase  are  due  in  part,  first  to 
centralization  of  creameries,  second,  to  mild  winters  in  certain 
sections  and  consequently  no  natural  ice,  third,  greater  con- 
venience if  properly  operated. 

Centralized  creameries  have  so  much  more  cooling  to  do 
than  a  local  creamery,  that  a  mechanical  refrigerating-plant 
best  serves  their  needs.  Often  centralized  plants  are  located 
in  large  cities  where  an  ice-manufacturing  plant  and  cold 
storage  plant  may  be  run  successfully  in  connection  with 
the  creamery.  Prof.  Erf  *  has  conducted  some  experiments 
relative  to  the  comparative  cost  of  the  two  systems  for  creamery 
use.  The  following  table  shows  the  results,  and  indicates  the 
comparative  cost  of  cooling  100  pounds  of  butter  to  30°  F., 
including  the  cost  of  cooling  the  cream  during  manufacturing 
processes.  These  figures  are  also  based  upon  a  run  of  10,000 
pounds  of  milk  per  day. 

1.  2.  3.  4. 

Natural-ice  system 20. Ic.       18.2c.       17.5c.       17. Ic. 

Mechanical  refrigeration.  .    .  .   17.8c.       17. Ic.       16.9c.       16.8c. 

The  different  columns  (1,  2,  3,  4)  indicate  different  insulating 
material  used,  which  cannot  here  be  elaborated  upon,  except 
to  say  that  it  pays  to  insulate  thoroughly. 

*  Creamery  Journal. 


COOLING  FACILITIES  FOR  CREAMERIES.  311 

The  above  results  indicate  that  mechanical  refrigeration 
is  a  little  the  cheaper.  The  cost  of  mechanical  refrigeration  is 
quite  constant  under  different  conditions,  while  the  cost  con- 
nected with  storing  and  using  natural  ice  will  vary  greatly 
according  to  different  localities. 

3.  Under  certain  conditions,  intentional  or  unintentional, 
a  creamery  must  be  run  without  the  use  of  ice,  and  without 
mechanical  refrigeration.  In  such  a  case  cold  water  is  a 
necessity.  One  of  the  authors  successfully  operated  a  creamery 
one  season  without  any  other  cooling  agent  than  water.  The 
winter  season  had  been  warm  and  no  ice  was  obtained  nor 
was  it  obtainable  at  a  reasonable  cost.  There  was  no  room 
in  the  creamery  for  a  mechanical  refrigerating-plant,  and  even 
if  there  had  been,  no  money  was  available  with  which  to  pur- 
chase such  cooling  facilities.  The  only  thing  to  do  was  to 
close  the  creamery  or  cool  with  water. 

The  latter  method  was  resorted  to.  The  creamery  was 
fortunate  in  having  an  unlimited  supply  of  pure  cold  water 
coming  from  a  mountain  stream. 

This  water  was  made  effective  for  cooling  purposes  by 
directing  a  constant  flow  through  a  galvanized  iron  tank  in 
the  refrigerator.  The  ice-box  on  the  inside  of  the  refrigerator 
was  removed,  and  a  closed  galvanized  iron  tank  put  in  its  place. 
This  tank  was  connected  up  with  an  inflow  and  overflow  at 
the  top.  A  faucet  for  draining  the  tank  was  provided  at  the 
bottom  in  one  corner.  The  tank  was  made  straight  on  the 
side  next  to  the  wall,  but  sloping  towards  the  wall  on  the  side 
facing  the  refrigerator  room.  This  was  done  so  as  to  allow 
the  dampness  or  sweat  collecting  on  the  outside  to  run  down 
the  sides  and  be  collected  in  a  trough,  which  conveyed  it  to 
the  outside.  A  trap  was  connected  with  this  outlet  so  as  not 
to  let  in  warm  air.  Such  an  arrangement  gave  very  good 
satisfaction,  though  not  so  effective  in  cooling  as  ice. 

The  cream  was  cooled  and  kept  cold  by  circulating  a  con- 
stant stream  of  water  through  the  vat-jackets.  The  tempera- 
ture of  the  water  was  never  above  50°  F. 


312  BUTTER-MAKING. 

The  butter  was  disposed  of  locally  while  fresh.  In  cream- 
eries where  it  is  necessary  to  hold  butter  any  length  of  time, 
this  system  is  undoubtedly  less  satisfactory,  but  under  above 
mentioned  conditions  it  gave  good  satisfaction. 

The  water-tank  should  never  be  made  from  wood,  as  wood 
is  a  very  poor  conductor  of  heat.  Heavy  galvanized  iron  is 
best. 

NATURAL  ICE  SYSTEM. 

Kind  of  Ice-house. — When  natural  ice  is  stored,  the  first 
consideration  is  a  good  ice-house  conveniently  located  to  the 
creamery  and  refrigerator.  When  the  creamery  is  first  planned 
and  built  the  ice-house  should  at  the  same  time  be  provided 
for.  The  ice-house  should  preferably  be  adjacent  to  the  re- 
frigerator, so  that  the  ice  can  be  transferred  directly  from  the 
house  into  the  cooler,  thus  obviating  much  loss  of  ice  and 
decreasing  labor. 

The  various  parts  of  the  building  embracing  the  many 
details,  will  not  here  be  enlarged  upon,  inasmuch  as  they  can 
be  more  advantageously  shown  in  plans.  Students  are  referred 
to  the  different  views  shown  on  pages  313-315,  317  and  318.* 

As  will  be  seen,  the  construction  of  the  ice-house  depends 
to  some  extent  upon  the  location  and  kind  of  refrigerator  to 
be  used.  There  are  at  least  two  different  ways  of  locating 
the  refrigerator  in  relation  to  ice-house:  (1)  Where  the  re- 
frigerator is  entirely  separate  from  the  ice-house,  the  ice  to  be 
transferred  and  placed  either  overhead  or  on  one  side  of  the 
refrigerator.  (2)  Where  the  refrigerator  is  combined  with 
the  ice-house  and  the  ice  is  not  moved  for  cooling  purposes. 
This  in  turn  may  be  arranged  so  as  to  have  the  ice  storage 
overhead  or  on  one  side  of  the  refrigerator.  The  ice-house 
needed  in  connection  with  this  second  method  differs  chiefly 
from  that  of  the  first  in  that  better  insulation  is  necessary 
and  no  ice-packing  material  is  used,  except  on  top.  This  latter 

*  N.  Y.  Produce  Review.  Showing  cooling  facilities  in  Albert  Lea 
Creamery,  Minn. 


COOLING  FACILITIES  FOR   CREAMERIES.  313 


1'r.iui  ~~> 


Cooling  Room 


,  In«i1»tioD"; 


SIMM  bUwMD 


PLAN 


SECTION 
Fio.  173. — Refrigerator  with  ice  overhead. 


314 


BUTTER-MAKING. 


Ill 

o 

o:      5 
O  5   § 

•  61 


o  o  | 


U 
DC 

O 


a  '.S  2 


COOLING  FACILITIES   FOR  CREAMERIES. 


315 


/Doors- 

$i  x  e'o.  &  M. 

•  Fencing.'" 
Waterproof 

Paper. 

^/ x  e'drop  — • 

siding.^/1 

I  Doors  lapped 

as  shown. 


w 

;^B 
Ixio'ifoists  -24  faen.  filled  with  shavings. 

4 

,^x6  D.  &M.  Fencing  _ 
-Waterproof  Paper. 
!  -%  Surfaced  Boards  . 

I  -^^"""^diT  ' 

•  "~  2  x  10  Studs  filled  with 

"S^-c^c*  ? 

!     1 

LJ 

\  .1^'surfaced  plank  for 
j    inside  door,  to  be  put  in 
^    as  the  ice  is  piled  up. 

: 

'i  e.  &  M.  Fencing. 
Waterproof  Paper. 
%  Surfaced  Boards. 


H  Surfaced  Boards.' 
Waterproof  Paper, 
x  6"b.  &  M.  Fencing'. 


^ Space  filled  with  shavings 
through  small  outside  door  at  top. 


8x8  Joists-2i  Cen.filled  with  planer  shaving 
Joists  to  slant  towards  center  of  house 


•S •t?.?,<3V"ji-i'' "°  Gravel  under  joists  well 
*—-gs-r-  tamped 


FIG.  175. — Construction  detail  of  ice-house. 


316  BUTTER-MAKING. 

method  of  creamery  refrigerators,  even  though  more  expensive, 
is  to  be  highly  recommended,  chiefly  because  labor  is  decreased, 
and  the  low  temperature  is  uniformly  maintained. 

Reasonable  high  ground  affords  a  good  location  for  an  ice- 
house. It  is  of  importance  that  the  ground  should  be  thor- 
oughly drained  before  building  the  ice-house.  If  the  ground 
is  high,  dry,  and  gravelly,  perhaps  no  drainage  is  needed, 
but  under  most  conditions  a  drain  should  be  run  through  the 
bottom.  This  drain  should  not  be  very  deep.  If  area  to  be 
drained  is  so  large  that  one  drain  will  not  carry  off  the  water, 
it  is  better  to  use  two  drains,  rather  than  to  have  one  deep  one. 

Size  and  Shape  of  Ice-house. — The  plan  of  the  ice-house 
should  be  as  nearly  square  as  consistent  with  room.  A  square 
building,  having  a  certain  length  of  wall  around  it,  will  hold 
more  ice  than  an  oblong  building  having  an  equal  number 
of  feet  of  outside  walls.  The  building  should  also  be  high  in 
proportion  to  width  and  length.  This  will  tend  to  preserve 
the  ice  as  proportionately  less  top  surface  is  exposed  to  the  air. 

The  size  of  the  building  will  vary  according  (1)  to  amount 
of  milk  handled  at  the  creamery,  (2)  whether  ice  is  sold  from 
creamery,  and  (3)  whether  ice  is  used  for  any  other  purposes, 
such  as  ice-cream  freezing,  cream  shipping,  etc.  For  creamery 
uses,  the  only  basis  on  which  to  estimate  is  the  amount  of 
milk  received. 

For  example,  suppose  a  creamery  is  receiving  12,000  pounds 
of  milk  daily.  This  milk  will  produce  about  2000  pounds  of 
cream  and  about  600  pounds  of  butter.  Suppose  that  the 
cream  needs  to  be  cooled  from  90°  F.  down  to  40°  F.  or  a  range 
of  50°  F.  One  pound  of  ice  will  cool  about  142  pounds  of 
water  1°  F.  Calculations  are  made  with  water  as  basis.  The 
results  will  thus  be  a  little  too  high,  but  subsequent  corrections 
will  be  made.  If  one  pound  of  ice  will  cool  142  pounds  of 
cream  1°  F.,  it  will  require  50  pounds  of  ice  to  cool  that  amount 
of  cream  50°  F.  By  calculation  from  these  figures  we  find  that 
about  0.35  of  a  pound  of  ice  is  required  to  cool  each  pound 
of  cream  50°  F.  and  for  cooling  2000  pounds  of  cream  it  will 


COOLING  FACILITIES  FOR   CREAMERIES. 


317 


i"3 


|£ 


\  a 

=      CO 


M& fl fl-1 


§  i 


318 


BUT  TER-MA  KING. 


require  700  pounds.  If  it  takes  700  pounds  of  ice  daily  for 
cooling  the  cream  for  eight  months  of  the  year,  which  is  about 
the  time  the  cream  would  have  to  be  cooled  by  artificial  means, 


[,         [) 
I' 


XJOOK  fl1""!^  »,Z 


M        U 


H       H 


it  would  take  168,000  pounds  of  ice  per  year.  As  the  specific 
heat  of  cream  is  only  about  0.7,  the  final  amount  needed  for 
cooling  the  cream  would  be  only  117,600  pounds,  or  about 
59  tons. 


COOLING  FACILITIES   FOR   CREAMERIES.  319 

The  next  consideration  is  the  ice  needed  for  cooling  the 
butter.  Roughly  speaking,  there  will  be  about  600  pounds  of 
butter.  Suppose  the  butter  needs  to  be  cooled  30°  F.  Granting 
that  the  specific  heat  of  butter  is  the  same  as  that  of  water, 
it  would  require  30  pounds  of  ice  to  cool  142  pounds  of  butter 
30°  F.  There  will  therefore  be  needed  daily  126  pounds  of 
ice  for  cooling  the  butter.  As  the  specific  heat  of  butter  is 
only  about  0.4,  51  pounds  of  ice  are  necessary  daily.  For  eight 
months  12,240  pounds  will  be  needed.  The  amount  of  ice 
needed  in  a  refrigerator  above  that  needed  for  cooling  the 
butter  cannot  be  calculated.  We  may  count  on  25%  radia- 
tion and  25%  as  an  allowance  for  cooling  tubs  and  packages. 
The  total  ice  needed  for  cooling  the  butter  will  then  be  24,480 
pounds,  or  about  12J  tons. 

Counting  on  20%  loss  incidental  to  transportation  and 
melting  in  the  ice-house,  89  tons  of  ice  are  needed  for  cooling 
the  cream  and  butter  the  number  of  degrees  mentioned  above. 

One  cubic  foot  of  ice  at  32°  F.  weighs  57.5  pounds.  If 
1  cubic  foot  of  ice  weighs  57.5  pounds,  89  tons  would  occupy 
a  space  equal  to  3093  cubic  feet,  and  would  require  an  ice- 
house of  dimensions  approximately  as  follows:  16  ft.  high, 
14  ft.  wide,  and  14  ft.  long.  These  dimensions  are  given  only 
as  examples.  The  height,  width,  and  length  may  need  to  be 
changed  to  conform  with  local  conditions.  One  thing  should 
be  kept  in  mind,  it  is  always  better  to  have  an  ice-house  a  little 
too  large  rather  than  too  small. 

Filling  the  Ice-house. — The  chief  objects  to  be  sought  in 
packing  ice  into  an  icehouse  already  properly  constructed, 
are :  first,  to  exclude  circulation  of  air  through  the  mass  of  ice 
and  thus  prevent  melting;  second,  to  pack  it  in  such  a  manner 
that  it  can  easily  be  removed  in  whole  blocks;  third,  to  pack 
it  with  such  material  that  it  will  leave  the  ice  as  clean  as  is 
consistent  with  other  important  sought  objects. 

The  packing  material  which  is  most  commonly  used  in  the 
central  western  States  is  sawdust.  This  is  very  efficient  in 
excluding  air,  lasting,  and  usually  cheap,  but  soils  the  ice, 


320  BUTTER-MAK1XG. 

so  that  considerable  water  needs  to  be  used  with  which  to  rinse 
it.  As  a  consequence  of  this  latter,  considerable  ice  is  wasted. 
Straw  is  used  successfully.  It  leaves  the  ice  much  cleaner, 
but  is  not  so  effective  in  preserving  the  ice.  Shavings  are 
good,  but  as  a  rule  are  too  expensive  and  not  available.  Some 
use  no  packing  material  other  than  ice  and  snow.  When  the 
blocks  of  ice  are  put  into  the  ice-house,  they  are  packed  closely 
together.  A  man  with  a  hatchet  chips  the  block  of  ice  in 
such  a  way  as  to  fit  them  snugly  together.  The  small  cracks 
are  filled  with  fine  ice  and  snow.  The  experience  of  the  authors 
is  that,  by  this  method,  the  blocks  of  ice  are  likely  to  solidly 
freeze  together,  so  the  ice  cannot  be  removed  without  break- 
ing it  up  into  irregular  pieces.  This  is  hard  work,  and  con- 
siderable ice  is  wasted. 

Another  method  of  filling  ice-houses  in  successful  use  is 
that  of  running  a  small  layer  of  water  into  the  building  and 
allowing  it  to  freeze.  The  doors  in  the  ice-house  are  opened 
during  a  protractive  period  of  cold  weather.  The  bottom  of 
the  ice-house  is  covered  with  building-paper.  Water  is  run 
on  top  of  this  and  allowed  to  freeze  until  a  layer  of  ice  about 
a  foot  in  thickness  has  been  obtained.  Then  another  layer  of 
paper  is  made  to  cover  the  ice  and  more  water  flooded  on 
and  frozen.  This  process  is  continued  until  the  ice-house 
is  filled.  The  paper  between  the  layers  prevents  the  ice 
from  freezing  into  one  solid  mass,  and  facilitates  the  removal 
of  the  ice. 

When  the  ice  is  stored  in  an  insulated  house,  combined 
with  the  refrigerator,  no  packing  material  is  used  except  on 
the  top  of  the  ice.  Shavings  are  good  to  pile  on  the  top  of  ice 
when  the  ice-house  has  been  filled.  They  are  clean  and  effective 
in  preserving  the  ice. 

The  cost  of  filling  an  ice-house  with  natural  ice,  obtainable 
within  a  distance  of  about  eight  miles,  will  vary  in  different 
localities,  but  may  be  said  to  range  between  $0.60  and  $1.25 
per  ton.  The  creamery  furnishes  a  man  to  pack  it  into  the 
ice-house. 


COOLING  FACILITIES    FOR    CREAMERIES.  321 

Source  of  Ice. — The  ice  for  creamery  use  should  be  ob- 
tained from  as  pure  water  as  possible.  A  large  running  stream 
is  always  better  than  a  small  polluted  stream.  Usually  the 
creamery  can  cooperate  with  butchers,  restaurants,  hotel- 
men,  and  other  local  ice-users  in  building  a  dam  in  a  suitable 
stream.  The  ice  can  also  as  a  rule  be  harvested  cheaper  by 
cooperation. 

Some  creameries  have  constructed  ice-ponds  near  the  ice- 
house. If  there  is  a  clay  or  impervious  bottom,  this  works 
successfully  and  economically.  The  pond  is  filled  and  kept 
filled  from  the  creamery  water-supply  or  from  a  tile  drain  inlet. 
Care  should  be  taken  not  to  use  stagnant  water  and  water 
in  which  weeds  and  other  rubbish  have  been  allowed  to  accu- 
mulate. The  pond  should  be  deep  enough  so  that  the  water 
will  not  freeze  to  the  bottom  and  produce  dirty  ice.  The  pond 
should  also  be  filled  with  water  to  overflowing  when  freezing 
is  begun,  otherwise  slush  and  snow  are  likely  to  accumulate 
together  with  dust  from  the  fields  and  roads,  producing  impure 
ice. 

The  ice  is  best  when  frozen  from  the  top  down.  A  hole  is 
bored  and  kept  open  in  the  ice  during  the  freezing  process. 
Through  this  opening  the  pond  is  supplied  with  water  as  rapidly 
as  it  subsides.  When  the  water  is  solidly  up  against  the  bottom 
of  the  ice  it  will  show  in  the  opening  or  hole  in  the  ice. 

To  construct  an  ice-pond  on  gravelly  soil  is  useless,  and  to 
pack  such  a  pond  with  a  sufficiently  thick  layer  of  clay  to  pre- 
vent leakage  of  water  is  under  most  conditions,  impracticable. 

USAGE  OF  ICE  IN  COOLING  CREAM. 

1.  Directly. 

2.  Indirectly. 

1.  The  cooling  of  cream  in  creameries  by  putting  ice  directly 
into  the  cream  has  been  much  practiced  in  the  past.  The 
method  is  yet  used  considerably,  especially  where  the  old 
open  vats  are  still  in  use.  Some  of  these  open  vats  are  jacketed 


322  BUTTER-MAKING. 

and  some  are  riot.  Cream  in  un jacketed  vats  could  not  well 
be  cooled  in  any  other  way  than  by  using  ice  directly  in  the 
cream  and  stirring  until  cold.  To  keep  cold  any  length  of 
time,  considerable  excess  of  ice  needs  to  be  used. 

Such  a  method  of  cooling  cream  has  its  advantages  as  well 
as  disadvantages.  The  latter,  however,  clearly  outweighs 
the  former. 

The  advantages  are  that  the  cream  can  be  cooled  in  a  very 
short  time,  and  it  does  not  require  any  special  investment 
for  up-to-date  ripening-vats,  nor  special  machinery  for  the 
purpose  of  pumping  the  cooling  medium. 

The  chief  disadvantages  are :  First,  impurities  and  un- 
desirable germs  are  liable  to  be  introduced,  which  would  injure 
the  quality  of  the  cream  and  otherwise  work  harm  to  the 
quality  and  keeping  property  of  the  butter;  second,  the  melt- 
ing of  the  ice  would  dilute  the  cream.  This  would  render 
the  cream  less  sour,  impart  a  marked  flat,  insipid  taste  to  the 
cream  and  butter,  and  produce  more  buttermilk  which,  if  it 
contained  a  certain  per  cent  fat,  would  mean  a  greater  loss 
of  fat  during  the  churning  process. 

The  use  of  ice  directly  in  the  cream  for  cooling  purposes 
should  not  be  resorted  to  unless  it  is  necessary.  With  the 
best  quality  of  cream  this  method  is  still  more  unsatisfactory, 
as  it  greatly  lowers  the  quality  of  butter.  With  cream  in 
very  poor  condition  previous  to  ripening,  the  chances  for 
lowering  the  quality  of  butter  are  not  so  great. 

2.  The  cooling  of  cream  with  ice  indirectly  is  by  far  the 
best  method.  With  the  use  of  our  up-to-date  ripening-vats, 
the  cooling  of  cream  is  an  easy  matter.  But  where  the  creamery 
is  already  in  possession  of  a  good  open  vat  and  the  manage- 
ment not  disposed  to  discard  it  to  install  a  new  one,  the  ques- 
tion is  different. 

Some  open  vats  have  a  jacket  and  special  open  space  at 
one  end  for  holding  crushed  ice.  These  vats  will  control  and 
hold  temperature  better  than  those  with  just  a  jacket  around. 
The  cooling  of  cream  on  a  large  scale  by  circulating  ice-water 


COOLING  FACILITIES  FOR  CREAMERIES.  323 

through  the  jacket,  at  best,  is  a  slow  process.  Usually  too 
slow  to  be  effective  and  practical. 

This  cooling  process  is  carried  out  by  mixing  the  ice  and 
water  together  in  a  separate  vat  to  which  a  rotary  pump  is 
attached,  forcing  the  water  through  the  jacket  and  again 
returned  to  the  ice  and  water-tank  to  be  cooled.  The  slow- 
ness of  this  cooling  process  can  in  a  measure  be  overcome  by 
mixing  salt  with  the  ice  and  water.  This  will  cause  the  ice 
to  melt  faster,  and  consequently  cool  the  brine  to  a  lower 
degree  of  temperature  than  was  possible  to  obtain  with  water 
and  ice. 

In  case  it  is  desirable,  a  set  of  coils  can  be  made  which  will 
fit  into  the  open  vat.  The  inlet  and  outlet  of  these  coils  can 
be  connected  up  by  means  of  rubber  hose  with  the  pipes  con- 
veying the  brine  to  and  from  the  ripener.  The  coils  can  be 
made  to  move  up  and  down,  by  means  of  a  rope  attached  to 
and  leading  from  the  coils  through  a  pulley  near  the  loft  and 
fastened  to  a  small  crank  at  the  end  of  a  shaft.  When  the 
shaft  turns  the  crank  will  also  turn  and  cause  the  coils  in  the 
vat  to  move  up  and  down.  In  the  absence  of  a  special  up-to- 
date  ripener,  this  manner  of  cooling  works  very  satisfactorily. 

A  butter  refrigerator  containing  a  tank,  as  already  de- 
scribed, could  be  cooled  by  pumping  brine  through  it  in  similar 
manner,  as  described  for  cream  cooling,  except  that  no  coils 
are  needed. 

MECHANICAL  REFRIGERATION. 

Application  of  in  Creameries. — Mechanical  refrigeration  has 
been  considered  expensive  and  impracticable  on  a  small  scale 
until  within  a  few  years.  The  science  of  producing  cold  arti- 
ficially has  been  simplified  and  reduced  to  such  a  practical 
basis  that  it  is  now  used  in  many  large  as  well  as  smaller 
plants  where  formerly  natural  ice  was  used  altogether.  Where 
at  least  10,000  pounds  of  milk,  or  its  equivalent  in  cream, 
are  received  daily  during  the  summer  months,  mechanical 
refrigeration  is  considered  practicable. 


324  BUTTER-MAKING. 

On  another  page  a  table  of  comparative  cost  of  natural  ice 
and  mechanical  refrigeration  is  given.  It  was  also  stated  in 
that  connection  that  the  cost  of  mechanical  refrigeration 
would  vary  under  different  conditions.  The  chief  factors 
affecting  the  cost  of  mechanical  refrigeration  may  be  said  to 
be  similar  to  those  affecting  the  economic  running  of  the  re- 
maining machinery,  such  as  kind  of  fuel  used,  skill  of  fireman, 
style  and  condition  of  boiler,  proportion  of  boiler  power  to 
work  done,  upon  the  correlative  size  of  all  machinery,  upon 
kind  of  insulation  and  care  of  cooling-rooms,  and  upon  effi- 
ciency of  compressor  and  whole  refrigerating  system. 

Chemicals  Used  for  Mechanical  Refrigeration. — The  most 
common  substances  used  in  mechanical  refrigeration  are  am- 
monia and  carbonic  acid.  A  number  of  others  are  in  use,  but 
from  a  creamery  standpoint,  these  only  are  of  importance. 
Ammonia  is  used  chiefly.  It  is  efficient,  cheap,  and  not  so 
dangerous  to  life  and  property  as  are  some  of  the  others. 
Anhydrous  ammonia  has  a  boiling-point  of  27°  below  zero 
at  atmospheric  pressure.  The  latent  heat  of  ammonia  is  also 
great.  Ammonia  has  great  chemical  stability,  and  is  not 
explosive  in  nature.  Ammonia  attacks  copper  and  brass, 
but  has  no  effect  upon  iron  and  steel  pipes.  If  ammonia 
should  escape  through  a  leak  into  a  room,  the  operator  can 
protect  himself  from  the  effects  of  the  gas  by  breathing  through 
a  wet  sponge  held  in  the  mouth.  Ammonia  leaks  may  be 
detected  by  holding  a  glass  rod  dipped  in  hydrochloric  acid 
to  the  place  where  the  leak  may  be.  When  ammonia  comes 
in  contact  with  hydrochloric  acid,  white  fumes  are  formed. 

Carbonic  acid  is  used  considerably  in  Europe,  and  is  chiefly 
favored  because  the  gas  is  not  highly  poisonous;  in  case  of 
leak  it  does  not  spoil  contents  of  refrigerator,  and  it  liquefies 
at  a  high  temperature  (90°  to  100°  F.),  and  is  therefore  favored 
in  tropical  climes. 

Principles  of  Producing  Cold  Artificially. — The  chief  principle 
involved  in  producing  artificial  cold  is  that  when  a  substance 
passes  from  a  liquid  into  a  gaseous  state,  a  definite  amount  of 


COOLING  FACILITIES  FOR   CREAMERIES.  325 

latent  heat  is  absorbed.  When  water  in  a  kettle  on  the  stove 
begins  to  boil  and  passes  off  into  steam,  no  higher  temperature 
can  be  reached.  No  matter  how  much  heat  is  applied  under 
those  same  conditions,  the  temperature  remains  the  same. 
This  extra  heat  is  used  in  transforming  the  water  into  steam. 
If  this  steam  were  confined,  and  that  heat  removed,  by  cooling, 
the  steam  would  again  pass  into  a  liquid  state.  We  are  familiar 
with  the  coolness  produced  by  rapid  evaporation  of  perspira- 
tion from  the  body.  Mechanical  refrigeration  is  virtually  a 
process  of  evaporation  of  the  cooling  media,  during  which 
heat  is  absorbed  and  liquefaction  of  the  cooling  medium  by 
compression  and  cooling  to  remove  that  absorbed  heat.  To 
increase  the  ability  of  the  cooling  medium  to  absorb  heat  it 
is  compressed  and  liquefied.  So  we  might  say  that  any  com- 
pression refrigerating  system  has  three  separate  operations 
necessary  to  form  the  complete  cycle  of  mechanical  refrigeration, 
viz.: 

1.  Compression  of  the  ammonia  gas. 

2.  Condensation  of  the  ammonia  gas. 

3.  Expansion  of  the  ammonia  gas. 

1.  The  machine  which  causes  the  compression  of  the  am- 
monia gas  is  called  the  compressor.     In  construction  it  is  much 
like   a   steam-engine.     Small   machines   are   single,   but   large 
machines  are  double  acting.     Gas  is  drawn  in,  on  the  suction 
stroke,  compressed  and  discharged  on  the  return  stroke.     The 
pressure  generated  varies  between   120  and   175  pounds  per 
square    inch.     During  the  compression  heat  is  developed  in 
proportion  to  pressure  exerted.     The  greater  the  pressure  the 
higher  the  temperature  of  the  gas.     Part  of  the  heat  of  com- 
pression is  carried  off  by  means  of  a  continuous  stream  of 
water  running  through  a  jacket  around  the  cylinder. 

2.  From  the  compressor  the  gas  is  forced  through  the  pipes 
into  the  condensing  coils,  in  which  the  warm  compressed  gas 
is  cooled  still  more.    When  sufficient  heat  has  been  removed 
from  this  gas,  it  assumes  a  liquid  condition  and  is  ready  to 
expand  into  a  gaseous  form  for  the  purpose  of  absorbing  heat 


326  BUTTER-MAKING. 

and  producing  cold.  During  the  cooling  and  condensing  pro- 
cesses each  pound  of  ammonia  parts  with  about  560  units  of 
heat,  which  amount  can  again  be  absorbed  when  it  expands  into 
gas  at  the  lower  pressure. 

3.  This  liquefied  gas,  which  is  still  under  great  pressure,  is 
then  admitted  through  what  is  termed  the  expansion-valve. 
This  valve  is  especially  constructed  for  that  purpose,  and  has 
only  a  very  minute  opening  in  it  for  the  admission  of  the  liquid 
ammonia.  On  the  expansion  side  the  pressure  is  low  (20 
to  30  Ibs.).  As  the  liquid  ammonia  emerges  from  the  high- 
pressure  side  through  the  expansion-valve  into  the  expansion 
side,  it  forms  a  gas.  This  expanded  gas  may  then  be  circulated 
through  coils  for  cooling  purposes.  From  there  it  passes  back 
into  the  suction  side  of  the  compressor  ready  to  go  through 
another  similar  cycle. 

From  the  above  description  it  will  be  seen  that  there  are  two 
sides  to  the  system,  the  expansion  side  and  the  compression 
side.  The  compression  side  extends  from  the  compressor  to 
the  expansion-valve ;  the  expansion  side  from  the  expansion- 
valve  to  the  suction  side  of  the  compressor,  inclusive. 

Transferring  the  Cold. — The  methods  of  transferring  the 
cold  to  the  different  places  in  the  building  vary.  There  are 
two  systems,  viz.: 

1.  Direct  Expansion. 

2.  Brine  System. 

1.  By   the   direct-expansion   system   the    condensing-pipes 
of  the  system  are  extended  to  the  room  or  place  at  which  the 
cooling  is  to  be  done.     An  extended  set  of  expansion  coils  then 
convey  the  gas  which  absorbs  the  heat.     A  lower  temperature 
can  be  produced  by  this  method  than  with  the  brine  system. 

2.  In  the  brine  system  a  large  brine-tank  is  placed  some- 
where in  the  creamery  at  a  place  most  convenient  with  respect 
to   cooling.     This  tank   contains   a   strong  solution  of  brine. 
The  chief  reason  why  brine  is  used  in  preference  to  water  is  that 
brine   has   a   very    low    freezing-point.     This   will   vary   with 
different  degrees  of  saturation. 


COOLING    FACILITIES  FOR   CREAMERIES. 


327 


Either  one,  sodium  chloride  (common  salt),  or  calcium 
chloride,  may  be  used  for  brine.  The  latter  is  considered 
best  chiefly  because  it  is  not  so  hard  on  the  pipes  and  it  keeps 
the  brine  pipes  cleaner  than  does  a  salt  brine.  The  tables 
give  properties  of  brine  made  from  these  two  substances. 

SHOWING  PROPERTIES  OF  SOLUTION  OF  SALT.    (SIEBLY). 
(Chloride  of  Sodium.) 


Per  cent 
of  Salt  by 
Weight. 

Pounds 
Salt  per 
Gallon  of 
Solution. 

Degrees  on 
Salometer 
at  60°  F. 

Weight 
per  Gallon 
at  39"  F. 

Specific 
Gravity  at 
39°  F. 
4°  C. 

Specific 
Heat. 

Freezing- 
point 
Fahr. 

Freezing- 
point 
Celsius. 

1 

0.084 

4 

8.40 

1.007 

0.992 

30.5 

-  0.8 

2 

0.169 

8 

8.46 

1.015 

0.984 

29.3 

-   1.5 

2.5 

0.212 

10 

8.50 

1.019 

0.980 

28.6 

-   1.9 

3 

0.256 

12 

8.53 

1.023 

0.976 

27.8 

-   2.3 

3.5 

0.300 

14 

8.56 

1.026 

0.972 

27.1 

-   2.7 

4 

0.344 

16 

8.59 

1.030 

0.968 

26.6 

-  3.0 

5 

0.433 

20 

8.65 

1.037 

0.960 

25.2 

-   3.8 

6 

0.523 

24 

8.72 

1.045 

0.946 

23.9 

-  4.5 

7 

0.617 

28 

8.78 

1.053 

0.932 

22.5 

-   5.3 

8 

0.708 

32 

8.85 

1.061 

0.919 

21.2 

-  6.0 

9 

0.802 

36 

8.91 

1.068 

0.905 

19.9 

-  6.7 

10 

0.897 

40 

8.97 

1.076 

0.892 

18.7 

-  7.4 

12 

1.092 

48 

9.10 

1.091 

0.874 

16.0 

-   8.9 

15 

1.389 

60 

9.26 

1.115 

0.855 

12.2 

-11.0 

20 

1.928 

80 

9.64 

1.155 

0.829 

6.1 

-14.4 

24 

2.376 

96 

9.90 

1.187 

0.795 

1.2 

-17.1 

25 

2.488 

100 

9.97 

1.196 

0.783 

0.5 

-17.8 

26 

2.610 

104 

10.04 

1.204 

0.771 

-1.1 

-18.4 

PROPERTIES  OF  SOLUTION  OF  CHLORIDE  OF  CALCIUM.  (SIEBLY). 


Per  cent  by 
Weight. 

Specific  Heat. 

Specific  Gravity 
at  60°  Fahr. 

Freezing-point 
in  Degrees  Fahr. 

Freezing-point 
in  Degrees  Cel*. 

1 

0.996 

1.009 

31 

-  0.5 

5 

0.964 

1.043 

27.5 

-   2.5 

10 

0.896 

1.087 

22 

-  5.6 

15 

0.860 

1  .  134 

15 

-  9.6 

20 

0.834 

1.182 

5 

-14.8 

25 

0.790 

1.234 

-8 

-22.1 

The  expansion-coils  pass  through  the  brine-tank  and  cool 
the  brine.  Special  pumps  force  the  cold  brine  through  pipes 
to  the  cream  vat,  cooling  coils,  ice-cream  freezer,  etc. 


328  BUTTER  MAKING. 

For  creameries  the  brine  system  is  the  only  practical  sys- 
tem. It  is  preferred  because,  first,  cold  can  be  stored  in  an 
insulated  brine-tank  and  used  at  will  without  running  the  com- 
pressor. In  case  of  a  prolonged  stoppage  due  to  some  accident 
a  brine  made  by  a  mixture  of  ice-water  and  salt  could  be 
temporarily  substituted;  second,  less  ammonia  is  required  to 
charge  the  system;  third,  fewer  couplings  and  less  ammonia 
pipes  are  necessary.  This  latter  would  decrease  the  danger 
of  ammonia  leakage  and  cost  of  pipes. 


CHAPTER  XXII. 

ECONOMIC  OPERATION  OF  CREAMERY. 

INASMUCH  as  it  is  impossible  within  the  limited  space  in  this 
work  to  take  up  a  detailed  discussion  of  the  various  principles 
and  practices  of  operating  boilers,  engines,  mechanical  re- 
frigerators, and  other  creamery  machinery,  only  a  few  of  the 
chief  factors  common  to  creamery  practice  and  effecting  the 
economic  operation  shall  here  be  discussed.  For  more  com- 
plete information  students  are  referred  to  works  treating 
specially  of  these  phases. 

Firing  the  Boiler. — Much  fuel  can  be  wasted  and  saved  ac- 
cording to  the  completeness  with  which  the  combustion  occurs. 
This  again  depends  upon  the  manner  of  firing,  upon  the  regu- 
lation of  the  draught,  and  upon  the  kind  of  boiler.  The  fire 
on  the  grates  should  never  be  too  thick  nor  should  too  much 
coal  be  loaded  on  the  fire  at  any  one  time.  A  thin,  even  fire 
permits  of  a  more  complete  combustion  than  when  clinkers 
and  cinders  are  allowed  to  accumulate  on  bottom  of  fire,  and 
a  heap  of  unburned  coal  on  top.  By  this  latter  method  of 
firing,  the  grates  are  likely  to  be  injured. 

To  get  the  most  heat  from  the  coal  the  draught  should  be 
regulated.  The  combustible  part  of  the  coal  is  of  two  kinds: 
first,  the  fixed  carbon,  and  second,  the  volatile  matter.  The 
former  is  the  coke  or  the  part  of  coal  which  is  seen  on  the  grates 
as  a  mass  of  glowing  fire.  The  latter  consists  of  the  gases 
which  pass  off  when  a  certain  temperature  is  reached,  and  which, 
when  mixed  with  a  certain  amount  of  air  at  a  given  tem- 
perature, will  burn.  The  heavy  black  trail  of  smoke  seen  rising 

329 


330 


BUTTER-MAKING. 


from  chimneys  is  partially  wasted  coal.  If  the  grates  are 
choked  with  a  thick  fire,  no  air  can  pass  through,  and  the 
volatile  parts  of  coal  pass  off  without  being  burned. 

Burning  Wood  or  Coal. — In  some  localities  this  question  is 
of  minor  importance,  as  conditions  may  be  such  that  coal 
only  can  be  used.  In  other  sections,  where  both  are  obtain- 
able, it  is  of  great  importance.  The  following  table*  shows 
figures  obtained  at  five  factories  in  Wisconsin  where  soft  coal 
was  burned  and  five  others  where  wood  was  used. 

DAILY  FUEL  USED  AT  SEVERAL  CREAMERIES. 


Pounds  of  Milk 
Skimmed 
per  Day. 

Pounds  of 
Soft  Coal 
Burned. 

Cost  of  Coal 
per  Ton. 

Estimated  Cost 
per  Day. 

3500 

500 

$3.55 

$0.90 

8000 

400 

3.00 

0.60 

23000 

1000 

4.05 

2.00 

6000 

300 

3.50 

0.50 

5300 

500 

3.15 

0.80 

Pounds  of  Milk 
Skimmed 
per  Day. 

Cords  of  Wood 
Burned. 

Price  per  Cord. 

Estimated  Cost 
per  Day. 

2000 

i 

$1.25 

$0.32 

3400 

* 

2.25 

0.37 

6500 

I 

1.25 

0.32 

3800 

i 

2.25 

0.37 

4500 

* 

1.80 

0.60 

These  are  the  best  obtainable  figures  of  comparison  under 
creamery  conditions. 

In  connection  with  burning  wood  the  dryness  of  it  is  an 
important  consideration.  If  the  wood  is  wet  its  power  of 
producing  heat  is  greatly  lessened.  A  certain  amount  of  heat 
is  used  in  evaporating  the  water  in  the  wood.  Air-dry  wood 
will  contain  from  12%  to  25%  water.  The  quality  of  coal 
is  another  variable  factor.  In  general,  and  from  table  below, 
it  might  be  said  that  2|  pounds  of  wood  are  equal  to  one  pound 
of  lump  coal. 


*  Farrington  in  Hoard's  Dairyman, 


ECONOMIC  OPERATION  OF  CREAMERY.  331 

The  following  comparative  table  is  given  by  Kent: 

Hickory  or  hard  maple,  weight  per  cord  4500  Ibs.  =  1800  to  2000  Ibs.  of  coal. 
White  oak  "       "      "     3850    "  =1540  to  1715    "    "     " 

Poplar,  chestnut  and  cedar  "       "      "     2350    '  '  =  940  to  1050    "    "     " 
Pine  "       "      "     2000    "  =  800  to    925    "    "     " 

Whether  a  creamery  can  economically  use  slack  or  lump 
coal  is  another  question  worth  considering.  Slack  coal  is  used 
very  little  in  local  creameries,  first,  because  it  is  more  difficult 
to  use  in  firing.  Usually  help  is  scarce,  and  coal  which  requires 
less  attention  in  firing  than  slack,  is  preferred.  Second,  slack 
coal  is  subject  to  spontaneous* combustion  and  likely  to  set 
buildings  afire.  Some,  if  not  all  insurance  companies,  dis- 
criminate against  creameries  using  slack  coal  as  fuel.  Third, 
special  grates  (rocking  grates)  are  essential  to  get  best  results 
from  using  slack.  Fourth,  slack  coal  is  dirty  and  the  dust 
from  it  will  lodge  all  over  in  the  boiler  and  engine  room. 

Slack  coal,  where  conditions  are  at  all  favorable  for  its  use, 
is,  as  a  rule,  cheap  to  burn.  According  to  experimental  data, 
1  pound  of  slack  coal  will  produce  about  4  pounds  of  steam, 
and  1  pound  of  lump  coal  will  produce  about  6  pounds  of 
steam.  The  price  of  the  two  will  vary,  but  usually  the  rela- 
tion is,  slack  coal,  $1.25  per  ton;  lump  coal,  $3.25  per  ton. 
If  1  pound  of  lump  coal  produces  6  pounds  of  steam,  a  ton 
will  produce  12,000  pounds.  If  1  pound  of  slack  coal  produces 
4  pounds  of  steam,  to  produce  12,000  pounds  will  require 
2992  pounds  of  slack  coal,  which  would  cost  $1.87.  The 
difference  in  producing  12,000  pounds  of  steam  in  favor  of 
slack  coal  would  then  be  $1.38. 

Daily  Weighing  of  Coal  Used.  —  The  advantage  of  daily 
weighing  of  coal  used  in  creameries  cannot  be  too  strongly 
emphasized.  That  business  phase  of  creamery  work  has  been 
much  neglected  in  the  past.  If  the  coal  used  daily  is  not 
weighed,  a  serious  loss  or  leak  may  continue  without  detec- 
tion. Firing  the  boiler  is  a  daily  occurrence,  and  if  a  small 
loss  occurs,  the  total  loss  at  the  end  of  the  year  would  cut 
short  the  profits. 


332  BUTTER-MAKING. 

The  weighing  can  conveniently  be  done  by  fitting  a  box 
similar  to  an  enlarged  flat-sided  curd  pail  in  shape  on  a  pair 
of  platform  scales.  After  the  scale  and  box  have  been  pur- 
chased there  are  iic  additional  expenses  and  very  little  extra 
labor  required. 

Cleaning  the  Boiler. — The  amount  of  coal  used  will  vary 
with  several  factors,  viz. :  cleanliness  of  flues,  sediment  in  the 
boiler,  condition  of  fire,  kind  of  boiler,  steam  leaks,  pipe  in- 
sulation, etc.  The  two  first  factors  are  frequently  neglected. 
The  flues  should  be  cleaned  every  morning  before  the  day's 
run.  The  inside  of  the  boiler  should  be  kept  clean.  Heavy 
scale  on  the  inside  of  the  boiler  and  flues,  and  heavy  sedi- 
ments on  the  bottom  of  the  boiler,  should  never  be  allowed  to 
accumulate.  Some  water  naturally  contains  a  large  amount  of 
minerals  and  leaves  a  heavy  deposit  in  the  boiler.  The  oper- 
ator should  learn  to  know  the  condition  of  the  water,  and  the 
frequency  of  cleaning  the  inside  of  the  boiler  be  governed 
accordingly.  One  cleaning  per  month  is  sufficient  with  most 
water.  In  some  instances,  one  cleaning  per  week  is  necessary. 

The  collection  of  scale  and  sediment  within  the  boiler  affect 
the  economic  operation  in  at  least  three  ways:  First,  more 
fuel  is  needed;  second,  the  boiler  itself  is  likely  to  warp;  third, 
foaming  or  priming  of  the  boiler  is  likely  to  occur.  If  scale 
clings  to  the  flues  when  washed,  it  may  be  removed  by  putting 
some  sal-soda  and  water  into  the  boiler  and  boil  for  several 
hours.  Some  use  a  boiler  compound  for  preventing  scales. 
This  is  not  necessary,  nor  to  be  recommended  except  in  extreme 
cases  of  mineral  water.  The  boiler  should  be  frequently  blown 
off  at  low  pressure. 

Priming  of  Boilers. — When  considerable  water  passes  over 
with  the  steam  the  boiler  is  said  to  be  priming.  This  water 
in  the  steam  interferes  with  the  running  of  the  engine.  So 
much  water  in  the  steam  fills  the  engine-cylinder  and  results 
in  broken  piston  or  cylinder-head.  The  engine  jerks  and 
thumps  to  such  an  extent  that  there  is  danger  of  breaking  other 
parts  of  the  machinery. 


ECONOMIC    OPERATION  OF   CREAMERY.  333 

The  foaming  or  priming  of  boilers  is  due  chiefly  to: 

1.  Too  much  water  in  the  boiler. 

2.  Working  the  boiler  beyond  its  capacity. 

3.  Allowing  mud  and  minerals  to  accumulate  in  boiler. 

4.  Using  too  much  of  certain  boiler  compounds. 

5.  Some  water  naturally  contains  a  large  percentage  of 

certain  minerals  which  are  conducive  to  foaming. 
The  Injector. — The  injector  on  the  boiler  frequently  causes 
the  operator  some  annoyance  by  refusing  to  work.     The  common 
causes  of  this  are: 

1.  Too  low  boiler  steam  pressure. 

2.  Steam  obtained  from  a  pipe  already  supplying  steam 

for  other  purposes. 

3.  Leaks  in  suction  pipe  due  to  shortage  of  supply  pipe 

or  holes  in  pipe. 

4.  Too  hot  supply  water. 

5.  Scale  in  injector,  preventing  proper  working  of  valves. 

6.  Steam  containing  too  much  water. 
Oil-separators. — Considerable  saving  can  be  accomplished  in 

a  creamery  if  the  exhaust  steam  is  utilized.  This  steam  may 
be  used  for  pasteurizing  the  skim-milk,  for  heating  the  milk 
previous  to  separation,  for  heating  the  creamery,  and  for  heat- 
ing the  water  for  the  boiler. 

The  exhaust  steam  contains  considerable  oil  and  should  be 
purified  before  it  is  used  for  any  other  purposes.  Several 
forms  of  these  steam  purifiers  are  on  the  market.  They  are 
simple,  inexpensive,  and  can  be  attached  to  the  exhaust-pipe 
of  any  engine. 

All  steam  and  water  pipes  should  be  carefully  drained  in 
the  winter  to  prevent  freezing. 

Belts,  Pulley  and  Speed  Calculation. — The  length  of  a  belt 
may  best  be  determined  by  measuring  over  the  two  pulleys 
with  a  tape  or  a  string. 

To  calculate  the  size  of  a  drive  pulley  when  the  speed 
of  it  is  known,  the  diameter  of  the  driver  pulley  is  multiplied 
by  its  speed,  the  product  divided  by  the  speed  of  the  driven 


334  BUTTER-MAKING. 

pulley,  the  quotient  will  be  the  diameter  or  size  of  the  needed 
pulley. 

To  calculate  the  speed  of  a  driven  pulley,  multiply  the 
diameter  by  the  speed  of  the  driver  pulley  and  divide  the 
product  by  the  diameter  of  the  driven  pulley;  the  quotient 
is  the  speed  or  number  of  revolutions  per  minute. 


APPENDIX. 


LEGAL  STANDARDS  FOR  MILK— DAIRY  LAWS* 

The  following  States  and  Territories,  viz.,  Alabama,  Arizona, 
Arkansas,  California,  Colorado,  Delaware,  Florida,  Louisiana, 
Mississippi,  Missouri,  Montana,  North  Dakota,  Texas,  and 
Wyoming,  have  established  no  legal  standard. 

The  Dominion  of  Canada,  Connecticut,  Idaho,  Illinois, 
Indiana,  Kansas,  Kentucky,  Maryland,  Nebraska,  Nevada, 
New  Mexico,  North  Carolina,  Oklahoma,  South  Dakota,  Ten- 
nessee, LTtah,  Virginia,  and  West  Virginia  have  general  laws 
prohibiting  dilution,  skimming,  or  other  adulteration. 

In  other  States  the  percentage  standards  are  as  follows: 

Specific  Total  TT.  . 

Gravity.  Solids. 

Per  Cent. 

District  of  Columbia 12.5  3.5 

Georgia 12  3.5 

Iowa 12.5  3 

Maine 12  3 

Massachusetts  (Apr.  to  Aug.,  inclusive) 12  3 

(Sept.  to  Mar.         "       ) 13  3.7 

Michigan 1.029-1.033  12.5  3 

Minnesota 13  3.5 

New  Hampshire 13 

New  Jersey 12  ... 

New  York 12  3 

Ohio  (May  and  June) 11.5  ... 

"     (July  to  April,  inclusive) 12  3 

Oregon 12  3 

Pennsylvania  f 1 .029-1 .033  12.5  3 

Rhode  Island 12  2.5 

South  Carolina 11.5  3 

Vermont  (May  and  June) 12  ... 

' '         (July  to  April,  inclusive) 12.5  ... 

Washington 11  3 

Wisconsin 3 

*  From  Wing  in  "  Milk  and  Its  Products." 
t  Applies  only  to  cities  of  the  second  and  third  classes. 

335 


336  MLTRIC  SYSTEM. 


METRIC  SYSTEM  * 

METRIC  SYSTEM  OF  WEIGHTS  AND  MEASURES  AND  TABLES 
FOR  THE  CONVERSION  OF  METRIC  WEIGHTS  AND  MEAS- 
URES INTO  CUSTOMARY  UNITED  STATES  EQUIVALENTS 
AND  THE  REVERSE. 

In  the  metric  system  the  meter  is  the  base  of  all  the  weight* 
and  measures  which  it  employs. 

The  meter  was  intended  to  be,  and  is  very  nearly,  one  tr  n- 
millionth  part  of  the  distance  measured  on  a  meridian  of  th  - 
earth  from  the  equator  to  the  pole,  and  equals  about  39.37 
inches  or  nearly  3  feet  3f  inches. 

The  meter  is  the  primary  unit  of  length. 

Upon  the  meter  are  based  the  following  primary  units:  the 
square  meter,  the  are,  the  cubic  meter  or  stere,  the  liter,  and 
the  gram. 

The  square  meter  is  the  unit  of  measure  for  small  surfaces; 
as  the  surface  of  a  floor,  table,  etc. 

The  are  is  the  unit  of  land  measure ;  this  is  a  square  whose 
side  is  10  meters  in  length,  and  which  contains  100  square 
meters. 

The  cubic  meter  or  stere  is  the  unit  of  volume;  this  is  a 
cube  whose  edge  is  1  meter  in  length. 

The  liter  is  the  unit  of  capacity;  this  is  the  capacity  of  a 
cube  whose  edge  is  one-tenth  of  a  meter  in  length. 

The  gram  is  the  unit  of  weight;  this  is  the  weight  of  dis- 
tilled water  contained  in  a  cube  whose  edge  is  the  one-hundredth 
part  of  a  meter;  a  gram  is  therefore  the  one-thousandth  part 
of  a  kilogram,  and  the  one-millionth  part  of  a  metric  ton. 

*  From  The  American  Chamber  of  Commerce. 


APPENDIX. 


337 


MEASURES  OP  LENGTH. 


Metric  Denominations  and  Values. 

Equivalents  in  Denominations  in 

Use. 

Myriameter.  .  .  . 

10,000  meters 
1,000  meters 
100  meters 
10  meters 
1  meter 
.  1  meter 
.01  meter 
.001  meter 

6.2137  miles 
.62137  mile,  or  3,280  ft.  10 
328  feet  1  inch 
393  .  7  inches 
39.37  inches 
3  .  937  inches 
.3937  inch 
.0394  inch 

in. 

Kilometer  

Hectometer  

Dekameter  

Meter  

Decimeter  

Centimeter  

Millimeter  

MEASURES  OF  SURFACE. 


Metric  Denominations  and  Values. 

Equivalents  in  Denominations 
in  Use. 

Hectare     .    . 

10,000  square  meters 
100  square  meters 
1  square  meter 

2.471  acres 
119.6  square  yards 
1,550  square  inches 

Are  

Centare  

MEASURES  OF  CAPACITY. 


Metric  Denominations  and  Values. 


Names. 

No.  of 
Liters. 

Cubic  Measure. 

Dry  Measure. 

Liquid  or  Wine 
Measure. 

Kiloliter     \ 
or  stere.  .  / 

1,000 

1  cubic  meter 

1.308  cu.  yds. 

264.17  gals. 

Hectoliter.  . 

100 

.1  cubic  meter 

2  bush.  3.35  pks. 

26.417  gals. 

Dekaliter.  .  . 

10 

10  cu.  decimeters 

9.08  quarts 

2.641  7  gals. 

Liter  

I 

1  cu.  decimeter 

.908  quart 

1.0567  qts. 

Deciliter.  .  .  . 

.1 

.1  cu.  decimeter 

6.1022  cu.  ins. 

.845  gill 

Centiliter.  .  . 

.01 

10  cu.  centimeters 

.6102  cu.  in. 

.338fl.oz. 

Milliliter.  .  .  . 

.001 

1  cu.  centimeter 

.061  cu.  in. 

.27  fl.  dram 

Equivalents  in  Denominations 
in  Use. 


338 


METRIC  SYSTEM. 


WEIGHTS. 


Metric    Denominations  and  Values. 

Equivalents  in  Deno- 
minations in  Use. 

Names. 

Number  of 
Grams. 

Weight  of  What 
Quantity  of  Water  at 
Maximum  Density. 

Avoirdupois  Weight. 

Metric  ton  

1,000,000 
100,000 
10,000 
1,000 
100 
10 
1 
.1 
.01 
.001 

1  cubic  meter 
1  hectoliter 
1  dekaliter 
1  liter 
1  deciliter 
10  cubic  centimeters 
1  cubic  centimeter 
.1  cubic  centimeter 
10  cubic  millimeters 
1  cubic  millimeter 

2204.6  pounds 
220.46  pounds 
22.046  pounds 
2.2046  pounds 
3.5274  ounces 
.3527  ounce 
15.432  grains 
1  .5432  grains 
.1543  grain 
.0154  grain 

Quintal  

Alyriagram  

Kilogram  or  kilo.  .  .  . 
Hectogram  

Dekagram   

Gram  

Decigram  

Centigram  

Milligram  

COMMON  MEASURES  AND  WEIGHTS,  WITH  THEIR  METRIC  EQUIVALENTS. 

The  following  are  some  of  the  Measures  in  common  use,  with  their  equiva- 
lents in  measures  of  the  Metric  System : 


(.Xn^nion 
Measure^, 

Equivalents. 

Common  Measures. 

Equivalents. 

1  inch 

2.54  centimeters 

1  cord 

3.624  steres 

1  foot 

.3048  meter 

1  liquid  quart 

.9465  liter 

1  yard 

.9144  meter 

1  gallon 

3.86  liters 

1  rod 

5.029  meters 

1  dry  quart 

1.101  liters 

1  mile 

1.6093  kilometers 

1  peck 

8.811  liters 

1  square  inch 

6.452  sq.  centimeters 

1  bushel 

35.24  liters 

1  square  foot 

.0929  sq.  meter 

1  ounce  av'd'p 

28.35  grams 

1  square  yard 

.8361  sq.  meter 

1  pound  av'd'p 

.4536  kilogram 

1  square  rod 

25.29  sq.  meters 

1  ton  (2000  Ibs.) 

.9072  metric  ton 

1  acre 

.4047  hectare 

1  ton  (2240  Ibs.) 

1.016  metric  ton 

1  square  mile 

259  hectares 

1  grain  troy 

.0648  gram 

1  cubic  inch 

16.39  cu.  centimeters 

1  ounce  troy 

31.104  grams 

1  cubic  foot 

.02832  cu.  meter 

1  pound  troy 

.3732  kilogram 

1  cubic  yard 

.7646  cu.  meter 

APPENDIX. 


339 


TABLE  FOR  THE  CONVERSION  OP  METRIC  WEIGHTS  AND  MEASURES  INTO  CUS- 
TOMARY UNITED  STATES  EQUIVALENTS  AND  THE  REVERSE. 

From  the  legal  equivalents  are  deduced  the  following  tables  for  convert- 
ing United  States  weights  and  measures. 

METRIC   TO   CUSTOMARY. 
LINEAR  MEASURE. 


Meters  =  Inches. 

Mete  rs  =  Feet. 

Me  ters  =  Yards. 

Kilometers  =  Miles. 

1=  39.37 

1=   3.28087 

1  =  1.093623 

1=0.62137 

2  =   78.74 

2=   6.56174 

2  =  2.187246 

2  =  1.24274 

3  =  118.11 

3=   9.84261 

3  =  3.280869 

3  =  1.86411 

4  =  157.48 

4  =  13.12348 

4  =  4.374492 

4  =  2.48548 

5  =  196.85 

5  =  16.40435 

5  =  5.468175 

5  =  3.10685 

6  =  236.22 

6  =  19.68522 

6  =  6.561738 

6  =  3.72822 

7  =  275.59 

7  =  22.96609 

7  =  7.655361 

7  =  4.34959 

8  =  314.96 

8  =  26.24696 

8=8.748984 

8  =  4.97096 

9  =  354.33 

9  =  29.52783 

9  =  9.842607 

9  =  5.59233 

CUSTPMARY   TO    METRIC. 
LINEAR  MEASURE. 


Inches  =  Centimeters. 

Feet  =  Meters. 

Meters  =  Yards. 

Miles  =  Kilometers. 

1=    2.54 

1=0.304798 

1=0.914393 

1=1.  60935 

2=    5.08 

2  =  0.609596 

2  =  1.828787 

2=   3.21869 

3=  7.62 

3  =  0.914393 

3  =  2.743179 

3=   4.82804 

4  =  10.16 

4  =  1.219191 

4  =  3.657574 

4=   6.43739 

5  =  12.70 

5  =  1.523989 

5  =  4.571966 

5=   8.04674 

6  =  15.24 

6  =  1.828787 

6  =  5.486358 

6=   9.65608 

7  =  17.78 

7  =  2.133584 

7  =  6.400753 

7  =  11.26543 

8  =  20.32 

8  =  2.438382 

8  =  7.315148 

8  =  12.87478 

9  =  22.86 

9  =  2.743179 

9  =  8.229537 

9  =  14.48412 

340 


METRIC  SYSTEM. 


SQUARE  MEASURE. 


CUBIC  MEASURE. 


g  « 

G  «            » 

E 

2         £ 

E 

E 

fl)   QJ             fli   r; 

$  v        aj  -*j 

3)  1>           4>"w 

£  —      *> 

•w                X> 

C3  C           oj  j- 

03  'S  =  Jj  2 

oej}  ~~  e3  Jj 

S*    =%" 

cr'"        cr1""1 

cr^        o^ 

^-  *-r        -^EZH 
3             9 

03             02 

CO             02 

co         co 

O           O 

o      5 

1=0.155 

1  =  10  .  764 

1=    1.196 

1=   35.315 

1=0.02832 

2  =  0.310 

2  =  21.528 

2=   2.392 

2=   70.631 

2  =  0.05663 

3  =  0.465 

3  =  32.292 

3=   3.588 

3  =  105.947 

3=0.08495 

4=0.620 

4  =  43.055 

4=   4.784 

4  =  141.262 

4=0.11326 

5  =  0.775 

5  =  53.819 

5=   5.980 

5  =  176.584 

5  =  0.14158 

6  =  0.930 

6  =  64.583 

6=   7.176 

6  =  210.899 

6  =  0.16990 

7  =  1.085 

7  =  75.347 

7=   8.372 

7  =  247.209 

7  =  0.19821 

8  =  1.  240 

8  =  86.111 

8=   9.568 

8  =  282.525 

8  =  0.22653 

9  =  1.395 

9  =  98.874 

9  =  10.764 

9  =  317.840 

9  =  0.25484 

SQUARE  MEASURE. 


LIQUID  MEASURE. 


c  • 

E 

1     <3| 

e 

«           E 

1      i 

Co    =     4)  0) 

4>  +j    ==     Q3  V 

13  "P              Q)   1> 

a  at      e 

03 

__      &3 

«M            53E 

b  S?         ^  a) 

t-  2  -—   ^-  "t; 

B          2 

£ 

pi  pl^           p^ 

3^           3^ 

'S  'id 

5                  3 

qj           ~* 

02             CO 

cr           cr 

02             CO 

02              02 

cS    I 

3         a 

3        o 

1=   6.452 

1=0.09290 

1=0.836 

1=0.338 

1  =  1.0567 

1=0.26417 

2  =  12.903 

2  =  0.18581 

2  =  1.672 

2  =  0.676 

2  =  2.1134 

2  =  0.52834 

3  =  19.354 

3=0.27871 

3  =  2.508 

3  =  1.014 

3  =  3.1700 

3=0.79251 

4  =  25.806 

4  =  0.37161 

4  =  3.344 

4  =  1.352 

4  =  4.2267 

4  =  1.05668 

5  =  32.257 

5  =  0.46452 

5  =  4.181 

5  =  1.691 

5  =  5.2834 

5  =  1.32085 

6  =  38.709 

6  =  0.55742 

6  =  5.017 

6  =  2.029 

6  =  6.3401 

6  =  1.  58502 

7  =  45.160 

7  =  0.65032 

7  =  5.853 

7  =  2.368 

7  =  7.3968 

7  =  1.84919 

8  =  51.612 

8  =  0.74323 

8  =  6.689 

8  =  2.706 

8  =  8.4534 

8  =  2.11336 

9  =  58.063 

9  =  0.83613 

9  =  7.525 

9  =  3.043 

9  =  9.5101 

9  =  2.37753 

DRY  MEASURE. 


LIQUID  MEASURE. 


2 

£ 

1    =| 
1          W 

E 
—           S 
S           ^ 

i  =  3 

«       § 

a 

1          E 

1=1 
1     1 

K 

•C            E 
§    =    S 
<y        3 

• 
g           E 

F-i      —      a) 

•a  "  | 

0           i-J 

1=   2.8375 
2=   5.6750 
3=  8.5125 
4  =  11.3500 
5=14.1875 
6  =  17.0250 
7  =  19.8625 
8  =  22.7000 
9  =  25.5375 

1=0.35242 
2  =  0.70485 
3  =  1.05727 
4  =  1.40969 
5  =  1.76211 
6  =  2.11454 
7  =  2.46696 
8  =  2.81938 
9  =  3.17181 

1=   2.957 
2=   5.915 
3=  8.872 
4  =  11.830 
5  =  14.787 
6  =  17.744 
7  =  20.702 
8  =  23.659 
9  =  26.616 

1=0.94636 
2  =  1.89272 
3  =  2.83908 
4  =  3.38544 
5  =  4.33180 
6  =  5.67816 
7  =  6.62452 
8  =  7.57088 
9  =  8.51724 

1=   3.78544 
2=   7.57088 
3  =  11.35632 
4  =  15.14176 
5  =  18.92720 
6  =  22.71264 
7  =  26.49808 
8  =  30.28352 
9  =  34.06896 

APPENDIX. 


341 


WEIGHT  (AVOIRDUPOIS). 


»                    3 

3 

W 

S                  tr  ^ 

8            "H 

S- 

Oj                  v.tl     . 

09                      K.tl      . 

•                        • 

=        tc 
•43  g             .fl 

a  M 

M      ^         e  §  *•* 

o          5<i  R 

t-    ^          "O   O   00 

S      &l 

•Co™    MO 

6         o 

3       o 

1*3               ® 

W            PH 

S           3 

1=0.1543 

1=735.274 

1=   2.20462 

1=0.9842 

2  =  0.3086 

2=   70.548 

2=   4.40924 

2  =  1.9684 

3  =  0.4630 

3  =  105.822 

3=   6.61386 

3  =  2.9526 

4  =  0.6173 

4  =  141.096 

4=   8.81849 

4  =  3.9368 

5  =  0.7716 

5  =  176.370 

5  =  11  .02311 

5  =  4.9210 

6  =  0.9259 

6  =  211.644 

6  =  13.22773 

6  =  5.9052 

7  =  1.0803 

7  =  246.918 

7  =  15.43235 

7  =  6.8894 

8  =  1.  2346 

8  =  282.192 

8  =  17.63697 

8  =  7.8736 

9  =  1.3889 

9  =  317.466 

9  =  19.84159 

9  =  8.8578 

3 

3            <K 

»5 

1 

"E     8 

• 

aj'o  M     5 

•S'S  M 

n      n 

_H  =    •-  g 

g  >'o  ~   6 

§•<'§.  '   J2 

Mo  II  'Co 

O       $ 

O       O 

(2  '   3 

h3      S 

1=  6.4799 

1=  28.3495 

1=0.45359 

1  =  1.0161 

2  =  12.9598 

2=  56.6991 

2  =  0.90919 

2  =  2.0321 

3  =  19.4397 

3=  85.0486 

3  =  1.36078 

3=3.0482 

4  =  25.9196 

4  =  113.3981 

4  =  1.81437 

4  =  4.0642 

5  =  32.3995 

5  =  141.7476 

5  =  2.26796 

5  =  5.0803 

6  =  38.8793 

6  =  170.0972 

6  =  2.72156 

6  =  6.0963 

7  =  45.3592 

7  =  198.4467 

7  =  3.17515 

7  =  7.1124 

8  =  51.8391 

8  =  226.7962 

8  =  3.62874 

8  =  8.1284 

9  =  58.3190 

9  =  255.1457 

9  =  4.08233 

9  =  9  1445 

INDEX. 


Abnormal  milk 54 

Acid,  butyric,  capric,  caprylic,  myristic,  oleic,  palmitic,  stearic 14 

carbonic,  hydrochloric,  phosphoric,  sulphuric 18 

citric 20 

lactic 213 

salicylic 99 

sulphuric 85 

tests 80,  208,  206 

Acidity  of  milk 78 

of  ripened  cream  in  relation  to  richness  of  cream 209 

of  starters 223 

tests  for 208 

Adhesion  of  milk 37 

Albumen  in  milk 16 

Albuminoids  in  milk 14 

Alkali  of  various  strengths  for  measuring  acid  in  milk  and  cream 80 

Amphoteric  reaction  of  milk 32 

Antiseptics 48 

Babcock  test  for  fat 84 

causes  and  remedies  for  common  defects  in  clear- 
ness of  fat  in 87 

Bacteria  in  milk,  aroma  and  flavor  producing 187 

as  a  cause  of  deterioration  of  butter 11 

classification  of 50 

conditions  favoring  development  of 45 

desirable  and  undesirable  in  cream  ripening 189 

number  of,  in  milk 51 

size  and  shape  of 45 

sources  of 52 

unfavorable  conditions  for 48 

Biological  changes  in  ripening  cream 210 

Boiler,  cleaning  of,  priming  of 332 

firing  with  wood  and  coal 330 

343 


344  INDEX. 

PAGE 

Breeds,  composition  of  milk  from  various 68 

Brine,  for  mechanical  refrigeration 327 

properties  of  NaCl  and  CaCl 327 

Bnne,  salting  butter  with 264 

soaking  tubs  in 271 

Butter,  appearance  of 292 

color  of 238,  291 

composition  of 281 

cost  of  manufacturing 278 

classification  and  grades  of,  as  outlined  by  N.  Y.  Mercantile  Ex- 
change   292 

exportation  cf 307 

flavor  of 290 

judging  and  grading  of 286 

keeping  in  creameries 276,  310,  313,  314 

making  of,  on  farm 169 

mottled,  causes  and  remedy 263 

packing  of 271,  275 

printing  of 274 

rancid,  and  cause  of 11 

saltiness  of 292 

storing  in  creameries 276 

texture  or  body  of 290 

test  for  water  in. 87 

washing,  and  kind  of  wash-water 247 

working  of 266 

Buttermilk 227,  232,  247 

Butyrin 13 

Calculation  of  amount  of  salt  to  add  to  butter 256 

of  average  per  cent  fat 105 

of  churn  yield 109 

of  cream-raising  coefficient 113 

of  dividends 109 

of  overrun 107 

of  solids  in  milk  35 

of  speed,  pulleys,  belts 331 

Cans,  starter 225 

Care  of  cream  on  farm 158 

Casein  in  milk,  condition  of 15 

Centrifugal  separation  of  cream 129 

Changes  in  milk  and  cream,  chemical,  physical,  and  biological 210 

Chemical  changes  in  ripe  and  over-ripe  cream 213,  215 

Churn,  keeping  in  good  condition , 245 

Churn  yield,  calculation  of 109 

Churned  milk,  sampling 96 


INDEX.  345 

f^,  .  PAGE 

Churning,  amount  of  cream  for  a 233 

conditions  affecting 227 

definition  of 226 

difficult,  causes  and  remedy  for 243 

Churning  mixed,  sweet,  and  sour  cream 243 

nature  of  agitation  for „ 235 

richness  of  cream  for 231 

straining  of  cream  previous  to 238 

when  to  stop 239 

Citric  acid  in  milk 20 

Coal,  daily  weighing  of 331 

slack  vs.  lump-coal 331 

Color,  butter 238 

•Coloring  matter  in  milk 20,  31 

Composite  samples 99 

care  and  arrangement  of 1(  2 

preservatives  for 99 

sampling  apparatus  for 94 

Composition  of  butter 281 

of  colostrum  milk 54 

of  dairy  salts 262 

of  different  kinds  of  milk 2 

effect  of,  on  quality  of  butter 281 

of  salty  milk 55 

of  separator  slime 144 

of  tuberculous  milk 62 

Commercial  starters 217 

preparation  and  use  of 218 

Continuous  method  of  pasteurization 173 

"Cooley"  method  of  cream  separation 124 

Cooling  facilities,  water,  ice,  mechanical  refrigeration    309 

cost  of  natural  ice-system  vs.  mechanical  refrigeration 310 

systems 309 

Cows,  average  production  of 66 

breeds  of 68 

cost  of  keeping 66 

table  showing  profit  and  loss  in  keeping 67 

Cream,  acidity  of,  for  churning t 205 

care  of,  on  farm 158 

effect  of  cleanliness  on  quality  of 159 

grading  of 79 

methods  of  disposing  of 167 

mixing  of  different  qualities 202 

pasteurization  of 173 

of  sour 180 

richness  of • 137,  152 


346  INDEX. 

PAGE 

Cream,  ripening  of 187 

sampling  of 93 

specific  heat  of 38 

Creamery  sewage  disposal 278 

plans 276 

Deep-setting  system  of  cream  separation 124 

Difficult  churning,  causes  and  remedy 243 

Dilution,  effect  of,  on  creaming 128 

Disinfectants 48,  99,  246 

Electricity,  effect  of,  on  germs  in  milk 53 

Enzymes  in  milk 20 

effect  of  heat  on 41 

tests  for 42 

Exports  of  butter 296. 


Factories,  plan  of 2791 

Farrington's  test 208. 

Fat  in  butter 286 

m  milk 5 

composition  of 13 

condition  of ft 

effects  of  environment 76 

of  heat  on 42 

of  various  feeds  on  composition  of 75 

glycerides  of 8 

glycerine  in 14 

melting-point  of 12 

membrane  enveloping  fat  globules 91 

microscopical  appearance  of 6 

non-volatile 12 

paying  for,  as  compared  with  fat  in  cream lift 

separation  of 123 

size  of  globules 7 

testing  for 84 

volatile 11 

Feeds,  effects  on  milk 75 

Ferments  in  milk 44 

classes  of 44,  491 

favorable  and  unfavorable  condition  for 45,  48 

Fermentations,  detection  of 56,  81 

various  kinds  of 44,  55 

Filtration  of  water 250 

methods  and  effects  of 251 


IXDEX.  347 

PAGE 

Firing  the  boiler 329 

wood  vs.  coal,  comparative  cost  of 330 

Flavors  of  butter 290 

of  milk 18,  30,  40 

Food  for  bacteria 45 

Formula  for  calculating  churn  yield 109 

cream-raising  coefficient 113 

dividends 109 

overrun 107 

solids  in  milk 35 

Frozen  milk,  effects  of  freezing 96 

Galactase  in  milk 20 

Gases  in  milk,  eliminating 20,  184 

kinds  and  sources  of 18 

Gerber  fermentation  test 81 

Glassware  for  Babcock  test 86 

Grading  milk  and  cream 78 

Gravity  separation,  different  systems  of 123 

Gritty  butter 263 

Heat,  effects  of,  on  properties  of  milk 38,  82 

Heating  milk  previous  to  skimming 118 

Hegelund  method  of  milking. 71 

Hydraulic  method  of  separation 128 

Hydrogen  peroxide 42 

Ice-house,  size,  shape,  plans  of,  methods  of  filling 312 

Ice,  source  of,  usage  of 321 

Injector ,  working  of , 333 

Intermittant  method  of  pasteurization 173 

Judging  and  grading  butter 286 

standard  for 286 

Keeping  property  of  butter 192 

effect  of  salt  on 258 

Lactation  period,  effect  of,  on  milk  and  fat 74 

Lactochrome  in  milk 20 

Lactometer,  comparison  of  scales  on 34 

use  of 32 

Lecithin  in  milk 20 

Lime,  its  use  in  creameries 245 

Mammary  gland,  description  of 22 

inflammation  of 30 


348  IXDEX. 

PAGE 

Mann's  test 206 

Mechanical  refrigeration,   application  of 323 

chemicals  used  for,  principles  of 324 

direct  expansion,  and  brine  system 326 

Membrane  enveloping  fat  globules 9 

Mercantile  Exchange,  N.  Y.,  grades  of  butter.  .  . 292 

Metric  system  of  weights  and  measures 315 

Milk,  abnormal 54 

apportioning  skimmed 97 

bloody 56 

blue  and  yellow 54 

classification  of 1 

composition 2 

of,  from  different  animals 2 

definition  of 1 

effects  of  thunder-storms  on  souring  of 53 

fat  in  skimmed 123 

from  barren  and  spayed  cows 61 

grading  of 78 

necessity  of  good 89 

properties  of,  physical  and  chemical 31 

ropy 58 

salty 55 

sampling  of 93 

frozen,  churned,  and  sour 22,  96,  97 

secretion  of,  conditions  affecting 28 

theories 25 

specific  gravity  of 32 

total  solids  of 3 

tuberculous  cows' 62 

variation  in  quality  of,  and  causes 65 

Milking,  frequency  of 68 

manner  of 70 

Milking-machine,  power,  hand,  tnd  foot 70-72 

Mottles,  causes  of,  in  butter 263 

kinds  of 263 

prevention  of 264 

Natural  starters,  preparation  of 217 

New  York  Extras  defined 293 

Non-volatile  fats 12 

Nuclein  in  milk 20 

Oil  separator 333 

Olein,  effect  of  variation  of,  on  softness  of  butter 12 

Opacity  of  milk s 31 


INDEX.  349 


PAGE 


Organized  ferments 44 

Over-ripe  cream 205  215 

Overrun,  definition  and  calculation  of 107 

factors  governing 108 

Packing  butter,  for  exhibitions 275 

kind  and  size  of  package 270 

preparation  of  tubs  previous  to 271 

Palmitin 12 

Pasteurization,  advantages  of 184 

cost  of 183 

definition  and  methods  of 1 73 

disadvantages  of 186 

factors'to  consider  in ]  75 

of  sour  cream 180 

use  of,  direct  steam  in 1 74 

Pasteurizer,  durability  and  efficiency 175 

Paying  for  fat  in  cream  as  compared  with  fat  in  milk 116 

Physical  changes  in  cream 210 

Proteids  in  milk,  as  a  cause  of  mottles  in  butter 264 

kinds  of 14 

Quevenne  lactometer 33 

Rancid  butter,  causes  of 11 

Receiving  milk  and  cream 78 

Refrigeration,  artificial,  natural 309,  323 

transferring  cooling  media 326 

Richness  of  cream  from  centrifugal  separator 137 

from  gravity  separation 125 

Ripening  cream,  artificial 199 

kinds  of  acids  produced  from.  . 214 

natural 198 

purposes  of 187 

stirring  of  cream  during 197 

temperature 194 

testing  cream  for  acidity  during 205 

when  churned  every  other  day 201 

Salting  butter,  amount  of  salt  to  use 256 

effects  of,  on  keeping  property  of  butter 258 

purpose  of 256 

with  brine 264 

Salt,  as  a  cause  of  mottles 263 

composition  of  American  and  Danish.  , 262 

condition  of,  when  added  to  butter 261 


350  INDEX. 

PAGE 

Salt,  effect  of,  on  keeping  property  of  butter 253 

of,  on  removal  of  buttermilk 259 

in  relation  to  water  in  butter .  259 

undissolved,  in  butter 263 

Samples,  average 104 

composite 99 

Sampling-tube 94 

Separation,  advantages  of  centrifugal 129 

centrifugal 129 

classification  of  centrifugal  machines 133 

conditions  affecting  completeness  of 139 

effect  of  speed  as  compared  with  diameter  on 143 

factors  governing  richness  of  cream 137 

gravity 123 

heating  milk  for 118 

history  and  development  of 130 

process  of  centrifugal 134 

results  from  different  methods  of 129 

Separator  farm,  introduction  and  development  in  Iowa 146 

reasons  for  introducing.       147 

Separator  slime,  composition  of 144 

Sewage-disposal  plants,  cuts  of 278 

Score-cards  for  butter , 287 

Shallow-pan  creaming 123 

Skimmed  milk,  apportioning.    97 

Standards,  legal,  for  milk 314 

Sterilization 173 

Statements,  annual 114 

patrons'  monthly 113 

Starter  cans 325 

Starters,  amount  to  use 196, 224 

definition,  history,  and  classification 216 

inoculation 220 

length  of  time  to  carry 222 

over-ripening  and  under-ripening  of 223 

preparation  of 217, 214 

Sugar  and  curd  in  butter 282 

in  milk 16 

Streaked  butter 263 

Table  showing  amount  of  acid  produced  from  a  definite  amount  of  sugar 

in  cream  ripening 214 

effect  of  temperature  on  growth  of  bacteria 46 

fat  and  total  solids  of  milk  from  various  breeds 68 

number  of  acid-  and  non-acid-producing  germs  in  ripe 

cream.  . 211 

profits  and  losses  in  keeping  cows 67 


INDEX.  351 

PAGE 

Taints  in  milk,  eliminating 19  49 

sources  of 18 

Temperature,  churning 227 

duration  of Hg 

effect  of,  on  bacterial  growth 46 

for  storing  butter 276 

pasteurization 173(  igi 

ripening 194 

separation 118 

wash-water 247 

Tests,  acid 80 

fat 84 

Tests,  fermentation 81 

pasteurized  milk 42 

Total  solids  of  milk,  variation  of 3 

Tubs,  preparation  and  kinds  of 271 

Udder,  external  appearance  of 29 

internal  structure  of 22 

Unorganized  ferments 44 

Urea  in  milk , 20 

Utensils,  cleaning 145,  1 59 

Variation  of  fat  in  milk,  causes  of 63 

Viscogen,  use  of 39 

Viscosity  of  milk 37 

restoration  of fir. 39 

Volatile  fats Jf. 11 

Washing  butter,  kind  of  wash-water  for 248 

purpose  of , .' 247 

Water  in  butter 241 

condition  of 242 

Water,  in  relation  to  salt  in  butter 259 

methods  of  purifying 250 

Wisconsin  curd  test 81 

Working  of  butter,  objects  and  effects  of 266 

Wood,  burning  in   creameries 330 

Working  of  butter,  objects  and  effects  of 266 


,r  milk.  . 


My.  - 


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